[
  {
    "question": "What is the ratio of the mass of an object to its volume?",
    "distractor3": "diameter",
    "distractor1": "frequency",
    "distractor2": "median",
    "correct_answer": "density",
    "support": "Density is the ratio of the mass of an object to its volume."
  },
  {
    "question": "Compounds with aluminum and silicon are commonly found in the clay fractions of soils derived from what?",
    "distractor3": "mineral ash",
    "distractor1": "volatile ash",
    "distractor2": "ground ash",
    "correct_answer": "volcanic ash",
    "support": "Compounds with aluminum and silicon are commonly found in the clay fractions of soils derived from volcanic ash. One of these compounds is vermiculite, which is formed in reactions caused by exposure to weather. Vermiculite has the following formula: Ca0.7[Si6.6Al1.4]Al4O20(OH)4. (The content of calcium, silicon, and aluminum are not shown as integers because the relative amounts of these elements vary from sample to sample. ) What is the mass percent of each element in this sample of vermiculite?."
  },
  {
    "question": "What are hydrocarbons most important use?",
    "distractor3": "electricity",
    "distractor1": "lightsource",
    "distractor2": "food",
    "correct_answer": "fuel",
    "support": "Hydrocarbons have a wide variety of important uses, but their most important use is as fuels."
  },
  {
    "question": "Collision frequency is greater for what category of catalysts, which also tend to be more sensitive to temperature and more 'expensive'?",
    "distractor3": "contiguous",
    "distractor1": "heterogeneous",
    "distractor2": "analogous",
    "correct_answer": "homogeneous",
    "support": "Heterogeneous catalysts are easier to recover. Collision frequency is greater for homogeneous catalysts. Homogeneous catalysts are often more sensitive to temperature. Homogeneous catalysts are often more expensive. Saylor URL: http://www. saylor. org/books."
  },
  {
    "question": "An electrostatic attraction between two ions that have exchanged what?",
    "distractor3": "protons",
    "distractor1": "neutrons",
    "distractor2": "quasars",
    "correct_answer": "electrons",
    "support": "An electrostatic attraction between two ions that have exchanged electrons."
  },
  {
    "question": "Mechanical waves can only trave through what?",
    "distractor3": "water",
    "distractor1": "light",
    "distractor2": "air",
    "correct_answer": "matter",
    "support": "The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium ( plural , media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid."
  },
  {
    "question": "What do you call materials that have low resistance to electric current?",
    "distractor3": "good insulator",
    "distractor1": "electromagnets",
    "distractor2": "poor conductors",
    "correct_answer": "electric conductors",
    "support": "Materials that have low resistance to electric current are called electric conductors . Many metals—including copper, aluminum, and steel—are good conductors of electricity. The outer electrons of metal atoms are loosely bound and free to move, allowing electric current to flow. Water that has even a tiny amount of impurities is an electric conductor as well."
  },
  {
    "question": "What does k stand for on the periodic table?",
    "distractor3": "calcium",
    "distractor1": "aluminum",
    "distractor2": "magnesium",
    "correct_answer": "potassium",
    "support": "Q: The table shown in the Figure above is called the periodic table of the elements. Each symbol stands for a different element. What do you think the symbol K stands for?."
  },
  {
    "question": "If you examine eyeglasses for nearsighted people, you will find the lenses are thinnest in the center and of what shape?",
    "distractor3": "square",
    "distractor1": "convex",
    "distractor2": "asymmetrical",
    "correct_answer": "concave",
    "support": "Discussion The negative power indicates a diverging (or concave) lens, as expected. The spectacle produces a case 3 image closer to the eye, where the person can see it. If you examine eyeglasses for nearsighted people, you will find the lenses are thinnest in the center. Additionally, if you examine a prescription for eyeglasses for nearsighted people, you will find that the prescribed power is negative and given in units of diopters."
  },
  {
    "question": "What property of materials describes the ease in which they can be molded into thin sheets?",
    "distractor3": "rigidity",
    "distractor1": "plasticity",
    "distractor2": "permeability",
    "correct_answer": "malleability",
    "support": "A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Silver is a shiny metal that conducts electricity very well. It can be molded into thin sheets, a property called malleability. Salt is dull and brittle and conducts electricity when it has been dissolved into water, which it does quite easily. Physical properties of matter include color, hardness, malleability, solubility, electrical conductivity, density, melting points , and boiling points ."
  },
  {
    "question": "The white of an egg becomes opaque when cooked because what are insoluble and solidify?",
    "distractor3": "fatty acids",
    "distractor1": "acetic proteins",
    "distractor2": "calcium molecules",
    "correct_answer": "denatured proteins",
    "support": ""
  },
  {
    "question": "What pigment do slow fibers contain?",
    "distractor3": "iron",
    "distractor1": "melolin",
    "distractor2": "hemoglobin",
    "correct_answer": "myoglobin",
    "support": "Which of the following statements is true? a. Fast fibers have a small diameter. Fast fibers contain loosely packed myofibrils. Fast fibers have large glycogen reserves. Fast fibers have many mitochondria. Which of the following statements is false? a. Slow fibers have a small network of capillaries. Slow fibers contain the pigment myoglobin. Slow fibers contain a large number of mitochondria. Slow fibers contract for extended periods. Cardiac muscles differ from skeletal muscles in that they ________. are striated b. utilize aerobic metabolism."
  },
  {
    "question": "What is caused by the reaction of nonmetal oxides with water in the atmosphere?",
    "distractor3": "yellow rain",
    "distractor1": "ozone rain",
    "distractor2": "carbon rain",
    "correct_answer": "acid rain",
    "support": "Acid rain is caused by the reaction of nonmetal oxides with water in the atmosphere. One such reaction involves nitrogen dioxide (NO2) and produces nitric acid (HNO3): 3NO2 + H2O → 2HNO3 + NO If 1.82 × 1013 g of NO2 enter the atmosphere every year due to human activities, potentially how many grams of HNO3 can be produced annually?."
  },
  {
    "question": "What are clathrin, copi and copii types of?",
    "distractor3": "artery coats",
    "distractor1": "replication coats",
    "distractor2": "pathogen coats",
    "correct_answer": "vesicle coats",
    "support": "The vesicle coat selects specific proteins as cargo. It selects cargo proteins by binding to sorting signals. These complexes cluster in the membrane, forming a vesicle buds, or coated pit . There are three types of vesicle coats: clathrin , COPI and COPII. Clathrin coats are found on vesicles trafficking between the Golgi and plasma membrane, the Golgi and endosomes, and the plasma membrane and endosomes. COPI ( coat protein complex) coated vesicles are responsible for transport from the cis -Golgi to the ER (retrograde transport), while COPII coated vesicles are responsible for transport from the ER to the Golgi (anterograde transport). Low-density lipoprotein (LDL) receptors aggregate in clathrin coated pits prior to internalization."
  },
  {
    "question": "A solenoid or coil wrapped around iron or certain other metals can form what kind of magnet?",
    "distractor3": "polarized magnet",
    "distractor1": "permanent magnet",
    "distractor2": "superconductor",
    "correct_answer": "electromagnet",
    "support": "An electromagnet is a solenoid wrapped around a bar of iron or other ferromagnetic material. The magnetic field of the solenoid magnetizes the iron bar."
  },
  {
    "question": "All alkaline earth metals have similar properties because they all have two what?",
    "distractor3": "caesium electrons",
    "distractor1": "balanced electrons",
    "distractor2": "transitions electrons",
    "correct_answer": "valence electrons",
    "support": "All alkaline Earth metals have similar properties because they all have two valence electrons. They readily give up their two valence electrons to achieve a full outer energy level, which is the most stable arrangement of electrons. As a result, they are very reactive, although not quite as reactive as the alkali metals in group 1. For example, alkaline Earth metals will react with cold water, but not explosively as alkali metals do. Because of their reactivity, alkaline Earth metals never exist as pure substances in nature. Instead, they are always found combined with other elements."
  },
  {
    "question": "In solids, particles can't overcome the force of attraction between them because they lack what?",
    "distractor3": "momentum",
    "distractor1": "gravity",
    "distractor2": "residual energy",
    "correct_answer": "kinetic energy",
    "support": "In solids, particles don’t have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do is vibrate. This explains why solids have a fixed volume and shape."
  },
  {
    "question": "The preferred phase a substance adopts can change with temperature. at low temperatures, most substances are solids (only helium is predicted to be a liquid at absolute zero). as the temperature increases, those substances with very weak intermolecular forces become gases directly in a process called this?",
    "distractor3": "Freezing Point",
    "distractor1": "speciation",
    "distractor2": "vaporization",
    "correct_answer": "sublimation",
    "support": "The preferred phase a substance adopts can change with temperature. At low temperatures, most substances are solids (only helium is predicted to be a liquid at absolute zero). As the temperature increases, those substances with very weak intermolecular forces become gases directly (in a process called sublimation, which will be discussed in Section 10.2 \"Phase Transitions: Melting, Boiling, and Subliming\"). Substances with weak interactions can become liquids as the temperature increases. As the temperature increases even more, the individual particles will have so much energy that the intermolecular forces are overcome, so the particles separate from each other, and the substance becomes a gas (assuming that their chemical bonds are not so weak that the compound decomposes from the high temperature). Although is it difficult to predict the temperature ranges for which solid, liquid, or gas is the preferred phase for any random substance, all substances progress from solid to liquid to gas in that order as temperature increases."
  },
  {
    "question": "Sulfur dioxide produced by burning coal is the leading cause of what deadly phenomenon?",
    "distractor3": "dioxide rain",
    "distractor1": "hail",
    "distractor2": "carbon rain",
    "correct_answer": "acid rain",
    "support": "Another problem with coal is that most coal contains sulfur. As it burns, the sulfur goes into the air as sulfur dioxide. Sulfur dioxide is the main cause of acid rain. Acid rain can be deadly to plants, animals, and whole ecosystems. Burning coal also puts a large number of small solid particulates into the air. These particles are dangerous to people, especially those who have asthma. People with asthma may end up in the hospital on days when particulate pollution is high."
  },
  {
    "question": "What causes water molecules to stay close to each other?",
    "distractor3": "friction",
    "distractor1": "oxidation",
    "distractor2": "surface tension",
    "correct_answer": "hydrogen bonding",
    "support": ""
  },
  {
    "question": "A phase diagram plots pressure and what else?",
    "distractor3": "precipitation",
    "distractor1": "oxygen",
    "distractor2": "volume",
    "correct_answer": "temperature",
    "support": "Summary The states of matter exhibited by a substance under different temperatures and pressures can be summarized graphically in a phase diagram, which is a plot of pressure versus temperature. Phase diagrams contain discrete regions corresponding to the solid, liquid, and gas phases. The solid and liquid regions are separated by the melting curve of the substance, and the liquid and gas regions are separated by its vapor pressure curve, which ends at the critical point. Within a given region, only a single phase is stable, but along the lines that separate the regions, two phases are in equilibrium at a given temperature and pressure. The lines separating the three phases intersect at a single point, the triple point, which is the only combination of temperature and pressure at which all three phases can coexist in equilibrium. Water has an unusual phase diagram: its melting point decreases with increasing pressure because ice is less dense than liquid water. The phase diagram of carbon dioxide shows that liquid carbon dioxide cannot exist at atmospheric pressure. Consequently, solid carbon dioxide sublimes directly to a gas."
  },
  {
    "question": "Nonmetals typically lack what capability, because they hold onto their electrons?",
    "distractor3": "mental capacity",
    "distractor1": "magnetic attraction",
    "distractor2": "repelling electricity",
    "correct_answer": "conducting electricity",
    "support": "Like most other nonmetals, fluorine cannot conduct electricity, and its electrons explain this as well. An electric current is a flow of electrons. Elements that readily give up electrons (the metals) can carry electric current because their electrons can flow freely. Elements that gain electrons instead of giving them up cannot carry electric current. They hold onto their electrons so they cannot flow."
  },
  {
    "question": "What gas consisting of three oxygen atoms is found largely in the stratosphere?",
    "distractor3": "smog",
    "distractor1": "carbon",
    "distractor2": "greenhouse",
    "correct_answer": "ozone",
    "support": "Air also includes water vapor. The amount of water vapor varies from place to place. That’s why water vapor isn’t included in Figure above . It can make up as much as 4 percent of the air. Ozone is a molecule made of three oxygen atoms. Ozone collects in a layer in the stratosphere."
  },
  {
    "question": "Density is considered what type of property, because it does not depend on the amount of material present in the sample?",
    "distractor3": "exensive property",
    "distractor1": "independent variable",
    "distractor2": "experimental property",
    "correct_answer": "intensive property",
    "support": "Density is an intensive property, meaning that it does not depend on the amount of material present in the sample. Water has a density of 1.0 g/mL. That density is the same whether you have a small glass of water or a swimming pool full of water. Density is a property that is constant for the particular identity of the matter being studied."
  },
  {
    "question": "Esters can be formed by heating carboxylic acids and alcohols in the presence of?",
    "distractor3": "an oxygen catalyst",
    "distractor1": "a nuclear catalyst",
    "distractor2": "an carbon catalyst",
    "correct_answer": "an acid catalyst",
    "support": "Esters can be formed by heating carboxylic acids and alcohols in the presence of an acid catalyst. This process is reversible, and the starting materials can be regenerated by reacting an ester with water in the presence of a weak base."
  },
  {
    "question": "What are materials that cannot conduct thermal energy efficiently known as?",
    "distractor3": "atmospheric insulators",
    "distractor1": "convection insulators",
    "distractor2": "physical insulators",
    "correct_answer": "thermal insulators",
    "support": "Materials that are poor conductors of thermal energy are called thermal insulators. Gases such as air and materials such as plastic and wood are thermal insulators."
  },
  {
    "question": "What kind of light bulb has a tungsten filament?",
    "distractor3": "sodium",
    "distractor1": "fluorescent",
    "distractor2": "translucent",
    "correct_answer": "incandescent",
    "support": "An incandescent light bulb like the one pictured in the Figure below produces visible light by incandescence. Incandescence occurs when something gets so hot that it glows. An incandescent light bulb contains a thin wire filament made of tungsten. When electric current passes through the filament, it gets extremely hot and emits light."
  },
  {
    "question": "What linear polymer of glucose units is found in plants and serves a structural purpose?",
    "distractor3": "sucrose",
    "distractor1": "frucose",
    "distractor2": "carbonate",
    "correct_answer": "cellulose",
    "support": "Cellulose is a structural polymer of glucose units found in plants. It is a linear polymer with the glucose units linked through β-1,4-glycosidic bonds."
  },
  {
    "question": "Ammonium nitrate and ammonium sulfate are used in fertilizers as a source of what?",
    "distractor3": "biofuel",
    "distractor1": "bacteria",
    "distractor2": "oxygen",
    "correct_answer": "nitrogen",
    "support": "Ammonium nitrate and ammonium sulfate are used in fertilizers as a source of nitrogen. The ammonium cation is tetrahedral. Refer to Section 2.1 \"Chemical Compounds\" to draw the structure of the ammonium ion."
  },
  {
    "question": "Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus. it releases energy when light nuclei are fused to form medium-mass nuclei. • fusion is the source of energy in what?",
    "distractor3": "galaxies",
    "distractor1": "Space",
    "distractor2": "orbits",
    "correct_answer": "stars",
    "support": "32.5 Fusion • Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus. It releases energy when light nuclei are fused to form medium-mass nuclei. • Fusion is the source of energy in stars, with the proton-proton cycle, 1."
  },
  {
    "question": "What are polymers of amino acids called?",
    "distractor3": "ribosomes",
    "distractor1": "polysaccharides",
    "distractor2": "monopeptides",
    "correct_answer": "polypeptides",
    "support": ""
  },
  {
    "question": "Molecules that are in continuous motion, travelling in straight lines and changing comprise what state of matter?",
    "distractor3": "plasma",
    "distractor1": "solids",
    "distractor2": "liquids",
    "correct_answer": "gases",
    "support": "Gases are composed of molecules that are in continuous motion, travelling in straight lines and changing."
  },
  {
    "question": "What kind of energy can both cause cancer and help in detecting and treating it?",
    "distractor3": "wind",
    "distractor1": "electricity",
    "distractor2": "heat",
    "correct_answer": "radiation",
    "support": "Harmless background radiation comes from radioactive elements in rocks and from cosmic rays. Other sources of radiation, such as radon, are harmful. They may cause illness in living things and damage materials such as metals. Radiation has several uses, including detecting and treating cancer."
  },
  {
    "question": "What are the most common forms of lasers today made of?",
    "distractor3": "spirogyra",
    "distractor1": "prisms",
    "distractor2": "light",
    "correct_answer": "silcon",
    "support": "Lasers are constructed from many types of lasing materials, including gases, liquids, solids, and semiconductors. But all lasers are based on the existence of a metastable state or a phosphorescent material. Some lasers produce continuous output; others are pulsed in bursts as brief as 10 −14 s . Some laser outputs are fantastically powerful—some greater than 10 12 W —but the −3 more common, everyday lasers produce something on the order of 10 W . The helium-neon laser that produces a familiar red light is very common. Figure 30.39 shows the energy levels of helium and neon, a pair of noble gases that work well together. An electrical discharge is passed through a helium-neon gas mixture in which the number of atoms of helium is ten times that of neon. The first excited state of helium is metastable and, thus, stores energy. This energy is easily transferred by collision to neon atoms, because they have an excited state at nearly the same energy as that in helium. That state in neon is also metastable, and this is the one that produces the laser output. (The most likely transition is to the nearby state, producing 1.96 eV photons, which have a wavelength of 633 nm and appear red. ) A population inversion can be produced in neon, because there are so many more helium atoms and these put energy into the neon. Helium-neon lasers often have continuous output, because the population inversion can be maintained even while lasing occurs. Probably the most common lasers in use today, including the common laser pointer, are semiconductor or diode lasers, made of silicon. Here, energy is pumped into the material by passing a current in the device to excite the electrons. Special coatings on the ends and fine cleavings of the semiconductor material allow light to bounce back and forth and a tiny fraction to emerge as laser light. Diode lasers can usually run continually and produce outputs in the milliwatt range."
  },
  {
    "question": "A phospholipid bilayer is made up of two layers of phospholipids, in which hydrophobic fatty acids are in the middle of the what?",
    "distractor3": "cell wall",
    "distractor1": "cells membrane",
    "distractor2": "skin",
    "correct_answer": "plasma membrane",
    "support": "A phospholipid is made up of a polar, phosphorus-containing head, and two long fatty acid (hydrocarbon), non-polar \"tails. \" That is, the head of the molecule is hydrophilic (water-loving), and the tail is hydrophobic (water-fearing). Cytosol and extracellular fluid - the insides and outsides of the cell - are made up of mostly water. In this watery environment, the water loving heads point out towards the water, and the water fearing tails point inwards, and push the water out. The resulting double layer is called a phospholipid bilayer. A phospholipid bilayer is made up of two layers of phospholipids, in which hydrophobic fatty acids are in the middle of the plasma membrane, and the hydrophilic heads are on the outside. An example of a simple phospholipid bilayer is illustrated in Figure below ."
  },
  {
    "question": "The noble gases are unreactive because of their?",
    "distractor3": "carbon content",
    "distractor1": "cell configurations",
    "distractor2": "proton configurations",
    "correct_answer": "electron configurations",
    "support": "The noble gases are unreactive because of their electron configurations. The noble gas neon has the electron configuration of 1 s 2 2 s 2 2 p 6 . It has a full outer shell and cannot incorporate any more electrons into the valence shell. The other noble gases have the same outer shell electron configuration even though they have different numbers of inner-shell electrons."
  },
  {
    "question": "Enzymes, antibodies, and muscle fiber are all types of what?",
    "distractor3": "acids",
    "distractor1": "lipids",
    "distractor2": "carbohydrates",
    "correct_answer": "proteins",
    "support": "Many important molecules in your body are proteins. Examples include enzymes, antibodies, and muscle fiber. Enzymes are a type of protein that speed up chemical reactions. They are known as \"biological catalysts. \" For example, your stomach would not be able to break down food if it did not have special enzymes to speed up the rate of digestion. Antibodies that protect you against disease are proteins. Muscle fiber is mostly protein ( Figure below )."
  },
  {
    "question": "What are formed by the loss of one or two electrons from an element?",
    "distractor3": "isotopes",
    "distractor1": "amines",
    "distractor2": "ions",
    "correct_answer": "cations",
    "support": "Cations are formed by the loss of one or two electrons from an element."
  },
  {
    "question": "The relative sizes of the atoms show several trends with regard to what visual method of organization?",
    "distractor3": "oscillations table",
    "distractor1": "vibrations table",
    "distractor2": "chemistry table",
    "correct_answer": "periodic table",
    "support": "The relative sizes of the atoms show several trends with regard to the structure of the periodic table. Atoms become larger going down a column and smaller going across a period."
  },
  {
    "question": "As you increase the temperature of a liquid what happens to the solubility of a solute?",
    "distractor3": "viscosity increases",
    "distractor1": "turbidity increases",
    "distractor2": "hydrophilic increases",
    "correct_answer": "solubility increases",
    "support": "Temperature affects the solubility of a solute. However, it affects the solubility of gases differently than the solubility of solids and liquids."
  },
  {
    "question": "What type of matter transmits light but scatters the light as it passes through?",
    "distractor3": "a mirror",
    "distractor1": "opaque matter",
    "distractor2": "refractive matter",
    "correct_answer": "translucent matter",
    "support": "Translucent matter is matter that transmits light but scatters the light as it passes through. Light passes through translucent objects but you cannot see clearly through them because the light is scattered in all directions. The frosted glass panes at the bottom of the window above are translucent."
  },
  {
    "question": "The solubility of gases, liquids, and solids are affected by changes in what?",
    "distractor3": "volume",
    "distractor1": "elevation",
    "distractor2": "friction",
    "correct_answer": "temperature",
    "support": "The solubility of gases, liquids, and solids are affected by changes in temperature."
  },
  {
    "question": "The distribution of thermal speeds depends strongly on temperature. as temperature increases, the speeds are shifted to higher values and the distribution is what?",
    "distractor3": "removed",
    "distractor1": "decreased",
    "distractor2": "improved",
    "correct_answer": "broadened",
    "support": "The distribution of thermal speeds depends strongly on temperature. As temperature increases, the speeds are shifted to higher values and the distribution is broadened."
  },
  {
    "question": "Coal, oil, and natural gas are examples of what, which forms when organic matter is under pressure for millions of years?",
    "distractor3": "nuclear fission",
    "distractor1": "complex carbohydrates",
    "distractor2": "solar fuels",
    "correct_answer": "fossil fuels",
    "support": "Millions of years ago, there were so many dead plants and animals that they could not completely decompose before they were buried. They were covered over by soil or sand, tar or ice. These dead plants and animals are organic matter made out of cells full of carbon-containing organic compounds (carbohydrates, lipids, proteins and nucleic acids). What happened to all this carbon? When organic matter is under pressure for millions of years, it forms fossil fuels. Fossil fuels are coal, oil, and natural gas."
  },
  {
    "question": "What is a combination of two or more substances in any proportion called?",
    "distractor3": "solvent",
    "distractor1": "combination",
    "distractor2": "solution",
    "correct_answer": "mixture",
    "support": "Not all combined substances are compounds. Some are mixtures. A mixture is a combination of two or more substances in any proportion. The substances in a mixture may be elements or compounds. The substances don’t combine chemically to form a new substance, as they do in a compound. Instead, they keep their original properties and just intermix. Examples of mixtures include salt and water in the ocean and gases in the atmosphere. Other examples are pictured in Figure below ."
  },
  {
    "question": "What kind of mixture consists of two or more phases, exemplified when a combination of oil and water forms layers?",
    "distractor3": "complex miture",
    "distractor1": "homogeneous",
    "distractor2": "simple mixture",
    "correct_answer": "heterogeneous",
    "support": "A phase is any part of a sample that has a uniform composition and properties. By definition, a pure substance or a homogeneous mixture consists of a single phase. A heterogeneous mixture consists of two or more phases. When oil and water are combined, they do not mix evenly, but instead form two separate layers. Each of the layers is called a phase."
  },
  {
    "question": "Proper chemical formulas for ionic compounds balance the total positive charge with what?",
    "distractor3": "total atomic charge",
    "distractor1": "total electric charge",
    "distractor2": "total ionic charge",
    "correct_answer": "total negative charge",
    "support": "Proper chemical formulas for ionic compounds balance the total positive charge with the total negative charge."
  },
  {
    "question": "What do factories and power plants use to remove particulates and waste gases from exhaust before releasing it?",
    "distractor3": "catalytic converters",
    "distractor1": "compressors",
    "distractor2": "mufflers",
    "correct_answer": "scrubbers",
    "support": "Scrubbers are used in factories and power plants. They remove particulates and waste gases from exhaust before it is released to the air. You can see how a scrubber works in Figure below ."
  },
  {
    "question": "Pure substances have a constant composition and can only be changed by what?",
    "distractor3": "carbon reactions",
    "distractor1": "radiation",
    "distractor2": "growth",
    "correct_answer": "chemical reactions",
    "support": "Pure substances have a constant composition and can only be changed by chemical reactions. They can be classified as either elements or compounds."
  },
  {
    "question": "What can be used to estimate the energy change of a chemical reaction?",
    "distractor3": "isoenergies",
    "distractor1": "bond magnitudes",
    "distractor2": "chemical energy",
    "correct_answer": "bond energies",
    "support": "Bond energies can be used to estimate the energy change of a chemical reaction. When bonds are broken in the reactants, the energy change for this process is endothermic. When bonds are formed in the products, the energy change for this process is exothermic. We combine the positive energy change with the negative energy change to estimate the overall energy change of the reaction. For example, in."
  },
  {
    "question": "Permanent dipole-dipole interactions are found in what kind of molecules?",
    "distractor3": "geologic",
    "distractor1": "directional",
    "distractor2": "dual",
    "correct_answer": "polar",
    "support": "Polar molecules have permanent dipole-dipole interactions."
  },
  {
    "question": "What delivers natural gas from rock that might not otherwise be obtainable?",
    "distractor3": "grinding",
    "distractor1": "rippling",
    "distractor2": "drilling",
    "correct_answer": "fracking",
    "support": "Fracking delivers natural gas from rock that might not otherwise be obtainable."
  },
  {
    "question": "What are cyclic compounds which have an element other than carbon atoms in the ring?",
    "distractor3": "polymeric compounds",
    "distractor1": "axial compounds",
    "distractor2": "homocyclic compounds",
    "correct_answer": "heterocyclic compounds",
    "support": "Note So far we have studied only aromatic compounds with carbon-containing rings. However, many cyclic compounds have an element other than carbon atoms in the ring. These compounds, called heterocyclic compounds, are discussed inChapter 15 \"Organic Acids and Bases and Some of Their Derivatives\", Section 15.13 \"Amines as Bases\". Some of these are heterocyclic aromatic compounds. Table 13.4 Some Drugs That Contain a Benzene Ring."
  },
  {
    "question": "Nitrogen & sulfur oxide combine with rain to form what?",
    "distractor3": "coarse rain",
    "distractor1": "toxic rain",
    "distractor2": "steam rain",
    "correct_answer": "acid rain",
    "support": "Nitrogen and sulfur oxides combine with rain to form acid rain."
  },
  {
    "question": "What is the name of matter that mechanical wave energy can only travel through?",
    "distractor3": "weight",
    "distractor1": "form",
    "distractor2": "solid",
    "correct_answer": "medium",
    "support": "The energy of a mechanical wave can travel only through matter. This matter is called the medium ( plural , media). The medium in Figure above is a liquid — the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. It’s important to note that particles of matter in the medium don’t actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and-forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on."
  },
  {
    "question": "What is able to occur because no surface is perfectly smooth?",
    "distractor3": "temperature",
    "distractor1": "mass",
    "distractor2": "tension",
    "correct_answer": "friction",
    "support": "Friction occurs because no surface is perfectly smooth. Even surfaces that look smooth to the unaided eye appear rough or bumpy when viewed under a microscope. Look at the metal surfaces in Figure below . The metal foil is so smooth that it is shiny. However, when highly magnified, the surface of metal appears to be very bumpy. All those mountains and valleys catch and grab the mountains and valleys of any other surface that contacts the metal. This creates friction."
  },
  {
    "question": "The seven unique crystal types are defined by what parts of themselves (parts that intersect at various angles)?",
    "distractor3": "eyes",
    "distractor1": "shards",
    "distractor2": "angles",
    "correct_answer": "faces",
    "support": "Crystals are classified into general categories based on their shapes. A crystal is defined by its faces, which intersect with one another at specific angles, which are characteristic of the given substance. The seven crystal systems are shown below, along with an example of each. The edge lengths of a crystal are represented by the letters , , and . The angles at which the faces intersect are represented by the Greek letters , , and . Each of the seven crystal systems differs in terms of the angles between the faces and in the number of edges of equal length on each face."
  },
  {
    "question": "What is the term for the attraction between oppositely charged atoms or ions?",
    "distractor3": "magnetic bond",
    "distractor1": "covalent bond",
    "distractor2": "neutron bond",
    "correct_answer": "ionic bond",
    "support": ""
  },
  {
    "question": "Although quite different, beryllium, magnesium, calcium, strontium, barium, and radium are all classified as what type of metals?",
    "distractor3": "acidic earth metals",
    "distractor1": "mucous earth metals",
    "distractor2": "detergent earth metals",
    "correct_answer": "alkaline earth metals",
    "support": "The Alkaline Earth Metals The alkaline earth metals are beryllium, magnesium, calcium, strontium, barium, and radium. Beryllium, strontium, and barium are rather rare, and radium is unstable and highly radioactive. In contrast, calcium and magnesium are the fifth and sixth most abundant elements on Earth, respectively; they are found in huge deposits of limestone and other minerals."
  },
  {
    "question": "What term refers to the amount of solute that can dissolve in a given amount of solvent at a given temperature?",
    "distractor3": "turbidity",
    "distractor1": "viscosity",
    "distractor2": "saturation",
    "correct_answer": "solubility",
    "support": "Solubility is the amount of solute that can dissolve in a given amount of solvent at a given temperature. Some solutes have greater solubility than others."
  },
  {
    "question": "What is considered to be the most common intrusive igneous rock?",
    "distractor3": "obsidian",
    "distractor1": "sandstone",
    "distractor2": "basalt",
    "correct_answer": "granite",
    "support": "Granite is the most common intrusive igneous rock. Pictured below are four types of intrusive rocks ( Figure below )."
  },
  {
    "question": "What can be described in terms of physical properties and chemical properties as well as its defining states?",
    "distractor3": "mass",
    "distractor1": "energy",
    "distractor2": "empty space",
    "correct_answer": "matter",
    "support": "Matter can be described in terms of physical properties and chemical properties."
  },
  {
    "question": "Radioactive isotopes have the same chemical properties as stable isotopes of the same element. still, how is radioactive isotope different from stable isotopes?",
    "distractor3": "they absorb light",
    "distractor1": "they absorb radiation",
    "distractor2": "they emit magnetism",
    "correct_answer": "they emit radiation",
    "support": "Radioactive isotopes have the same chemical properties as stable isotopes of the same element, but they emit radiation, which can be detected. If we replace one (or more) atom(s) with radioisotope(s) in a compound, we can track them by monitoring their radioactive emissions. This type of compound is called a radioactive tracer (or radioactive label). Radioisotopes are used to follow the paths of biochemical reactions or to determine how a substance is distributed within an organism. Radioactive tracers are also used in many medical applications, including both diagnosis and treatment. They are used to measure engine wear, analyze the geological formation around oil wells, and much more. Radioisotopes have revolutionized medical practice (see Appendix M), where they are used extensively. Over 10 million nuclear medicine procedures and more than 100 million nuclear medicine tests are performed annually in the United States. Four typical examples of radioactive tracers used in medicine are technetium-99 ( 99 , thallium-201 43 Tc) , iodine-131 ( 131 , and sodium-24 ( 24 . Damaged tissues in the heart, liver, and lungs absorb certain ( 201 81 Tl) 11 Na) 53 I) compounds of technetium-99 preferentially. After it is injected, the location of the technetium compound, and hence the damaged tissue, can be determined by detecting the γ rays emitted by the Tc-99 isotope. Thallium-201 (Figure 21.24) becomes concentrated in healthy heart tissue, so the two isotopes, Tc-99 and Tl-201, are used together to study heart tissue. Iodine-131 concentrates in the thyroid gland, the liver, and some parts of the brain. It can therefore be used to monitor goiter and treat thyroid conditions, such as Grave’s disease, as well as liver and brain tumors. Salt solutions containing compounds of sodium-24 are injected into the bloodstream to help locate obstructions to the flow of blood."
  },
  {
    "question": "Keratin is an intracellular fibrous protein that gives hair, nails, and skin their hardness and this?",
    "distractor3": "friction resistant properties",
    "distractor1": "heat resistant properties",
    "distractor2": "cold - resistant properties",
    "correct_answer": "water-resistant properties",
    "support": "The cells in all of the layers except the stratum basale are called keratinocytes. A keratinocyte is a cell that manufactures and stores the protein keratin. Keratin is an intracellular fibrous protein that gives hair, nails, and skin their hardness and water-resistant properties. The keratinocytes in the stratum corneum are dead and regularly slough away, being replaced by cells from the deeper layers (Figure 5.4)."
  },
  {
    "question": "Each f atom has one bonding pair and three lone pairs of what?",
    "distractor3": "protons",
    "distractor1": "ions",
    "distractor2": "megatrons",
    "correct_answer": "electrons",
    "support": "There are two different types of electrons in the fluorine diatomic molecule. The bonding electron pair makes the covalent bond. Each F atom has three other pairs of electrons that do not participate in the bonding; they are called lone electron pairs. Each F atom has one bonding pair and three lone pairs of electrons. Covalent bonds can be made between different elements as well. One example is HF. Each atom starts out with an odd number of electrons in its valence shell:."
  },
  {
    "question": "What type of rock makes up most of the earth?",
    "distractor3": "Sedimentary",
    "distractor1": "tuberous",
    "distractor2": "Metamorphic",
    "correct_answer": "igneous",
    "support": "Most of the Earth is made of igneous rock. The entire mantle is igneous rock, as are some areas of the crust. One of the most common igneous rocks is granite ( Figure below ). Many mountain ranges are made of granite. People use granite for countertops, buildings, monuments and statues. Pumice is also an igneous rock. Perhaps you have used a pumice stone to smooth your skin. Pumice stones are put into giant washing machines with new jeans and tumbled around. The result is stone-washed jeans!."
  },
  {
    "question": "Matter is composed of exceedingly small particles called what?",
    "distractor3": "ions",
    "distractor1": "crystals",
    "distractor2": "cells",
    "correct_answer": "atoms",
    "support": "Atomic Theory through the Nineteenth Century The earliest recorded discussion of the basic structure of matter comes from ancient Greek philosophers, the scientists of their day. In the fifth century BC, Leucippus and Democritus argued that all matter was composed of small, finite particles that they called atomos, a term derived from the Greek word for “indivisible. ” They thought of atoms as moving particles that differed in shape and size, and which could join together. Later, Aristotle and others came to the conclusion that matter consisted of various combinations of the four “elements”—fire, earth, air, and water—and could be infinitely divided. Interestingly, these philosophers thought about atoms and “elements” as philosophical concepts, but apparently never considered performing experiments to test their ideas. The Aristotelian view of the composition of matter held sway for over two thousand years, until English schoolteacher John Dalton helped to revolutionize chemistry with his hypothesis that the behavior of matter could be explained using an atomic theory. First published in 1807, many of Dalton’s hypotheses about the microscopic features of matter are still valid in modern atomic theory. Here are the postulates of Dalton’s atomic theory. Matter is composed of exceedingly small particles called atoms. An atom is the smallest unit of an element."
  },
  {
    "question": "An amine is an organic compound that can be considered to be a derivative of what?",
    "distractor3": "calcium",
    "distractor1": "nitrogen",
    "distractor2": "lead",
    "correct_answer": "ammonia",
    "support": "An amine is an organic compound that can be considered to be a derivative of ammonia (NH 3 ). The general structure of an amine can be abbreviated as R−NH 2 , where R is a carbon chain. However, similar to alcohols, amines can be primary, secondary, or tertiary."
  },
  {
    "question": "Elements have orbitals that are filled with what?",
    "distractor3": "photons",
    "distractor1": "particles",
    "distractor2": "ions",
    "correct_answer": "electrons",
    "support": "enters a d orbital. The valence electrons (those added after the last noble gas configuration) in these elements include the ns and (n – 1) d electrons. The official IUPAC definition of transition elements specifies those with partially filled d orbitals. Thus, the elements with completely filled orbitals (Zn, Cd, Hg, as well as Cu, Ag, and Au in Figure 6.30) are not technically transition elements. However, the term is frequently used to refer to the entire d block (colored yellow in Figure 6.30), and we will adopt this usage in this textbook. Inner transition elements are metallic elements in which the last electron added occupies an f orbital. They."
  },
  {
    "question": "What are the elements of group 17 (fluorine, chlorine, bromine, iodine, and astatine) called?",
    "distractor3": "antioxidants",
    "distractor1": "metals",
    "distractor2": "liquids",
    "correct_answer": "halogens",
    "support": "The elements of Group 17 (fluorine, chlorine, bromine, iodine, and astatine) are called the halogens . The halogens all have the general electron configuration n s 2 n p 5 , giving them seven valence electrons. They are one electron short of having full outer s and p sublevels, which makes them very reactive. They undergo especially vigorous reactions with the reactive alkali metals. In their pure elemental forms, chlorine and fluorine are gases at room temperature, bromine is a dark orange liquid, and iodine is a dark purple-gray solid. Astatine is so rare that its properties are mostly unknown."
  },
  {
    "question": "What is caused by the buildup of stress in the rocks?",
    "distractor3": "debris tilting",
    "distractor1": "ground fall",
    "distractor2": "ground dropping",
    "correct_answer": "ground tilting",
    "support": "There are other possible signs before an earthquake. The ground may tilt. Ground tilting is caused by the buildup of stress in the rocks. This may happen before a large earthquake, but it doesn't always. Water levels in wells may fluctuate. This is because water may move into or out of fractures before an earthquake. This is also an uncertain way to predict an earthquake. The difference in arrival times of P-waves and S-waves may decrease just before an earthquake occurs."
  },
  {
    "question": "A  polar covalent bond is a covalent bond between different atoms that attract the shared electrons by different amounts and cause an imbalance of what ?",
    "distractor3": "neutron distribution",
    "distractor1": "proton distribution",
    "distractor2": "ions distribution",
    "correct_answer": "electron distribution",
    "support": "EXAMPLE 13 Describe the bonding in the nitrite ion in terms of a combination of hybrid atomic orbitals and molecular orbitals. Lewis dot structures and the VSEPR model predict that the NO2− ion is bent. Given: chemical species and molecular geometry Asked for: bonding description using hybrid atomic orbitals and molecular orbitals Strategy: A Calculate the number of valence electrons in NO2−. From the structure, predict the type of atomic orbital hybridization in the ion. B Predict the number and type of molecular orbitals that form during bonding. Use valence electrons to fill these orbitals and then calculate the number of electrons that remain. C If there are unhybridized orbitals, place the remaining electrons in these orbitals in order of increasing energy. Calculate the bond order and describe the bonding. Solution: A The lone pair of electrons on nitrogen and a bent structure suggest that the bonding in NO 2− is similar to the bonding in ozone. This conclusion is supported by the fact that nitrite also contains 18 valence electrons (5 from N and 6 from each O, plus 1 for the −1 charge). The bent structure implies that the nitrogen is sp2 hybridized. B If we assume that the oxygen atoms are sp2 hybridized as well, then we can use twosp2 hybrid orbitals on each oxygen and one sp2 hybrid orbital on nitrogen to accommodate the five lone pairs of electrons. Two sp2 hybrid orbitals on nitrogen form σ bonds with the remaining sp2 hybrid orbital on each oxygen."
  },
  {
    "question": "Polymers can disassemble by the reverse process called what?",
    "distractor3": "electrolysis",
    "distractor1": "mitosis",
    "distractor2": "dehydration",
    "correct_answer": "hydrolysis",
    "support": ""
  },
  {
    "question": "Ionic bonds are formed between which ions?",
    "distractor3": "with the same charges",
    "distractor1": "with multiple charges",
    "distractor2": "with random charges",
    "correct_answer": "with opposite charges",
    "support": "Ionic bonds are formed between ions with opposite charges. For instance, positively charged sodium ions and negatively charged chloride ions bond together to make crystals of sodium chloride, or table salt, creating a crystalline molecule with zero net charge. Certain salts are referred to in physiology as electrolytes (including sodium, potassium, and calcium), ions necessary for nerve impulse conduction, muscle contractions and water balance. Many sports drinks and dietary supplements provide these ions to replace those lost from the body via sweating during exercise."
  },
  {
    "question": "What part is written first when naming an ionic compound?",
    "distractor3": "carbonate",
    "distractor1": "anion",
    "distractor2": "Atom",
    "correct_answer": "cation",
    "support": "Ionic compounds are named by writing the name of the cation followed by the name of the anion."
  },
  {
    "question": "What mineral is used in jewelry because of its striking greenish-blue color?",
    "distractor3": "lime",
    "distractor1": "aqua",
    "distractor2": "glass",
    "correct_answer": "turquoise",
    "support": "Diamonds have many valuable properties. Diamonds are extremely hard and are used for industrial purposes. The most valuable diamonds are large, well-shaped and sparkly. Turquoise is another mineral that is used in jewelry because of its striking greenish-blue color. Many minerals have interesting appearances. Specific terms are used to describe the appearance of minerals."
  },
  {
    "question": "How does adding salt to water affect the boiling point?",
    "distractor3": "maintains",
    "distractor1": "no difference",
    "distractor2": "reduces",
    "correct_answer": "increases",
    "support": "Salt is often added to boiling water when preparing spaghetti or other pasta. One reason is to add flavor to the food. Some people believe that the addition of salt increases the boiling point of the water. Technically, they are correct, but the increase is rather small. You would need to add over 100 grams of NaCl to a liter of water to increase the boiling point a couple of degrees, which is just not healthy."
  },
  {
    "question": "Burning fossil fuels releases what into the atmosphere?",
    "distractor3": "nitrogen dioxide",
    "distractor1": "carbon monoxide",
    "distractor2": "phosphorus dioxide",
    "correct_answer": "carbon dioxide",
    "support": "Burning organic material, such as fossil fuels, releases carbon dioxide."
  },
  {
    "question": "What protein is hair mostly made of?",
    "distractor3": "Actin",
    "distractor1": "coronin",
    "distractor2": "Dystrophin",
    "correct_answer": "keratin",
    "support": ""
  },
  {
    "question": "What is the term for the number of covalent bonds an atom can form?",
    "distractor3": "covalent number",
    "distractor1": "atomic number",
    "distractor2": "gradient",
    "correct_answer": "valence",
    "support": ""
  },
  {
    "question": "A carbon atom with 6 protons and 8 neutrons is more specifically known as?",
    "distractor3": "carbon 6",
    "distractor1": "carbon 12",
    "distractor2": "carbon 8",
    "correct_answer": "carbon 14",
    "support": "An example of a radioisotope is carbon-14. All carbon atoms have 6 protons, and most have 6 neutrons. These carbon atoms are called carbon-12, where 12 is the mass number (6 protons + 6 neutrons). A tiny percentage of carbon atoms have 8 neutrons instead of the usual 6. These atoms are called carbon-14 (6 protons + 8 neutrons). The nuclei of carbon-14 are unstable because they have too many neutrons. To be stable, a small nucleus like carbon, with just 6 protons, must have a 1:1 ratio of protons to neutrons. In other words, it must have the same number of neutrons as protons. In a large nucleus, with many protons, the ratio must be 2:1 or even 3:1 protons to neutrons."
  },
  {
    "question": "Control rods containing nuclides that very strongly absorb neutrons are used to adjust what?",
    "distractor3": "thermal flux",
    "distractor1": "nuclei flux",
    "distractor2": "fission flux",
    "correct_answer": "neutron flux",
    "support": "Control rods containing nuclides that very strongly absorb neutrons are used to adjust neutron flux. To produce large power, reactors contain hundreds to thousands of critical masses, and the chain reaction easily becomes self-sustaining, a condition called criticality. Neutron flux should be carefully regulated to avoid an exponential increase in fissions, a condition called supercriticality. Control rods help prevent overheating, perhaps even a meltdown or explosive disassembly. The water that is 235 used to thermalize neutrons, necessary to get them to induce fission in U , and achieve criticality, provides a negative."
  },
  {
    "question": "What is the result of a reaction between sulfur trioxide and water?",
    "distractor3": "hydrochloric acid",
    "distractor1": "nitric acid",
    "distractor2": "acetic acid",
    "correct_answer": "sulfuric acid",
    "support": "Sulfur trioxide gas reacts with water to form sulfuric acid. This is an unfortunately common reaction that occurs in the atmosphere in some places where oxides of sulfur are present as pollutants. The acid formed in the reaction falls to the ground as acid rain."
  },
  {
    "question": "What happens to atoms during a substitution reaction?",
    "distractor3": "disintegrate",
    "distractor1": "impaction",
    "distractor2": "fusion",
    "correct_answer": "replace another in a molecule",
    "support": "A substitution reaction is a reaction in which one or more atoms replace another atom or group of atoms in a molecule. Alkyl halides are formed by the substitution of a halogen atom for a hydrogen atom. When methane reacts with chlorine gas, ultraviolet light can act as a catalyst for the reaction."
  },
  {
    "question": "When water freezes, it expands in volume as what is formed?",
    "distractor3": "energy",
    "distractor1": "movement",
    "distractor2": "plasma",
    "correct_answer": "ice",
    "support": "Ice is an interesting and useful material. It can be used to cool food and keep it fresh. It can provide recreation, such as ice-skating. Ice can do great damage when it freezes – roads can buckle, houses can be damaged, water pipes can burst. All this happens because of a unique property of water and ice. When water freezes, it expands in volume as ice is formed."
  },
  {
    "question": "Which type of energy holds atoms together?",
    "distractor3": "curve energy",
    "distractor1": "atomic energy",
    "distractor2": "nuclear energy",
    "correct_answer": "bond energy",
    "support": "Atoms are held together by a certain amount of energy called bond energy."
  },
  {
    "question": "What is a substance or object that absorbs and dissipates heat but does not experience a corresponding increase in temperature?",
    "distractor3": "heat dispeller",
    "distractor1": "heat diffuser",
    "distractor2": "heat storer",
    "correct_answer": "heat sink",
    "support": "Water as a Heat Sink A heat sink is a substance or object that absorbs and dissipates heat but does not experience a corresponding increase in temperature. In the body, water absorbs the heat generated by chemical reactions without greatly increasing in temperature. Moreover, when the environmental temperature soars, the water stored in the body helps keep the body cool. This cooling effect happens as warm blood from the body’s core flows to the blood vessels just under the skin and is transferred to the environment. At the same time, sweat glands release warm water in sweat. As the water evaporates into the air, it carries away heat, and then the cooler blood from the periphery circulates back to the body core."
  },
  {
    "question": "Kinetic theory is the atomistic description of what as well as liquids and solids?",
    "distractor3": "fluids",
    "distractor1": "plasmas",
    "distractor2": "molecules",
    "correct_answer": "gases",
    "support": "13.4 Kinetic Theory: Atomic and Molecular Explanation of Pressure and Temperature • Kinetic theory is the atomistic description of gases as well as liquids and solids. • Kinetic theory models the properties of matter in terms of continuous random motion of atoms and molecules. • The ideal gas law can also be expressed as."
  },
  {
    "question": "What are the long carbon chains that make up lipids?",
    "distractor3": "nucleic acids",
    "distractor1": "proteins",
    "distractor2": "carbohydrates",
    "correct_answer": "fatty acids",
    "support": "Lipids are made up of long carbon chains called fatty acids. Like hydrocarbons, fatty acids may be saturated or unsaturated. Figure below shows structural formulas for two small fatty acids. One is saturated and one is unsaturated."
  },
  {
    "question": "What defines the behavior of a compound?",
    "distractor3": "location of atoms",
    "distractor1": "size of atoms",
    "distractor2": "area of atoms",
    "correct_answer": "group of atoms",
    "support": "In a compound, a group of atoms that define the behavior of the compound."
  },
  {
    "question": "Part of the fossil record, stromatolites belong to what rock group and are formed when minerals are precipitated out of water by prokaryotes in a microbial mat?",
    "distractor3": "crystalline",
    "distractor1": "metamorphic",
    "distractor2": "igneous",
    "correct_answer": "sedimentary",
    "support": "Stromatolites Fossilized microbial mats represent the earliest record of life on Earth. A stromatolite is a sedimentary structure formed when minerals are precipitated out of water by prokaryotes in a microbial mat (Figure 22.3). Stromatolites form layered rocks made of carbonate or silicate. Although most stromatolites are artifacts from the past, there are places on Earth where stromatolites are still forming. For example, growing stromatolites have been found in the Anza-Borrego Desert State Park in San Diego County, California."
  },
  {
    "question": "An alpha particle, which is relatively large and easily stopped by matter, is a type of what?",
    "distractor3": "free emission",
    "distractor1": "waste emission",
    "distractor2": "plant emission",
    "correct_answer": "radioactive emission",
    "support": "Alpha, beta, and gamma emissions have different abilities to penetrate matter. The relatively large alpha particle is easily stopped by matter (although it may impart a significant amount of energy to the matter it contacts). Beta particles penetrate slightly into matter, perhaps a few centimeters at most. Gamma rays can penetrate deeply into matter and can impart a large amount of energy into the surrounding matter. Table 11.1 \"The Three Main Forms of Radioactive Emissions\" summarizes the properties of the three main types of radioactive emissions. Table 11.1 The Three Main Forms of Radioactive Emissions."
  },
  {
    "question": "What collect sunlight on the roof of a house for energy?",
    "distractor3": "asphalt shingles",
    "distractor1": "infrared panels",
    "distractor2": "clay tiles",
    "correct_answer": "solar panels",
    "support": "Solar panels collect sunlight on the roof of this house. The energy can be used to run the household."
  },
  {
    "question": "What happens when oppositely charged regions of neighboring water molecules are attracted to each other?",
    "distractor3": "oxygen is released",
    "distractor1": "potassium bonds form",
    "distractor2": "metabolic bonds form",
    "correct_answer": "hydrogen bonds form",
    "support": ""
  },
  {
    "question": "Proteins may be defined as compounds of high molar mass consisting largely or entirely of chains of these?",
    "distractor3": "enzymes",
    "distractor1": "nucleic acids",
    "distractor2": "fatty acids",
    "correct_answer": "amino acids",
    "support": "Proteins may be defined as compounds of high molar mass consisting largely or entirely of chains of amino acids. Their masses range from several thousand to several million daltons (Da). In addition to carbon, hydrogen, and oxygen atoms, all proteins contain nitrogen and sulfur atoms, and many also contain phosphorus atoms and traces of other elements. Proteins serve a variety of roles in living organisms and are often classified by these biological roles, which are summarized in Table 18.1 \"Classification of Proteins by Biological Function\". Muscle tissue is largely protein, as are skin and hair. Proteins are present in the blood, in the brain, and even in tooth enamel. Each type of cell in our bodies makes its own specialized proteins, as well as proteins common to all or most cells."
  },
  {
    "question": "What does antifreeze do to the boiling point of coolant?",
    "distractor3": "has no effect",
    "distractor1": "lowers it",
    "distractor2": "accelerates it",
    "correct_answer": "raises it",
    "support": "Flickr: EvelynGiggles, modified by CK-12 Foundation. Antifreeze raises the boiling point of coolant . CC BY 2.0."
  },
  {
    "question": "What are waxes made up of?",
    "distractor3": "long - chain pyroclastic acids",
    "distractor1": "long - project fatty acids",
    "distractor2": "long-chain natural acids",
    "correct_answer": "long-chain fatty acids",
    "support": "Another category of lipid molecule is waxes. Waxes are esters of long-chain fatty acids and long-chain alcohols. Waxes are soft solids with generally low melting points and are insoluble in water. The Figure below shows the structure of cetyl palmitate, a natural wax present in sperm whales."
  },
  {
    "question": "Which two atoms are found in most organic compounds?",
    "distractor3": "magnesium and carbon",
    "distractor1": "hydrogen and magnesium",
    "distractor2": "potassium and carbon",
    "correct_answer": "hydrogen and carbon",
    "support": ""
  },
  {
    "question": "What is the process of soil dissolving in rain called?",
    "distractor3": "migration",
    "distractor1": "abrasion",
    "distractor2": "sedimentation",
    "correct_answer": "erosion",
    "support": "Mechanical weathering increases the rate of chemical weathering. As rock breaks into smaller pieces, the surface area of the pieces increases. With more surfaces exposed, there are more places for chemical weathering to occur. Let’s say you wanted to make some hot chocolate on a cold day. It would be hard to get a big chunk of chocolate to dissolve in your milk or hot water. Maybe you could make hot chocolate from some smaller pieces like chocolate chips, but it is much easier to add a powder to your milk. This is because the smaller the pieces are, the more surface area they have. Smaller pieces dissolve more easily."
  },
  {
    "question": "What is the smallest particle of an element that still has the properties of that element?",
    "distractor3": "neutron",
    "distractor1": "electron",
    "distractor2": "nucleus",
    "correct_answer": "atom",
    "support": "The smallest particle of an element that still has the properties of that element is the atom. All the atoms of an element are like one another, and are different from the atoms of all other elements."
  },
  {
    "question": "What type of molecules do hydrogen bonds hold together?",
    "distractor3": "carbon",
    "distractor1": "gas",
    "distractor2": "air",
    "correct_answer": "water",
    "support": "Hydrogen bonds hold adjacent water molecules together."
  },
  {
    "question": "What is the only way to transfer thermal energy without matter?",
    "distractor3": "evaporation",
    "distractor1": "ultraviolet light",
    "distractor2": "osmosis",
    "correct_answer": "radiation",
    "support": "Thermal radiation is one of three ways that thermal energy can be transferred. The other two ways are conduction and convection, both of which need matter to transfer energy. Radiation is the only way of transferring thermal energy that doesn’t require matter. To learn more about thermal radiation, watch “Radiation” at the URL below."
  },
  {
    "question": "In what kind of state are particles fixed in place relative to one another?",
    "distractor3": "liquid state",
    "distractor1": "hybrid state",
    "distractor2": "useful state",
    "correct_answer": "solid state",
    "support": "In the solid state, particles are fixed in place relative to one another. In the liquid and gas states, individual particles are free to move."
  },
  {
    "question": "What type of carbon compound is methane?",
    "distractor3": "alternating compounds",
    "distractor1": "dynamic organic compounds",
    "distractor2": "stable compounds",
    "correct_answer": "volatile organic compounds",
    "support": "Volatile organic compounds (VOCs) are carbon compounds, such as methane. VOCs are released by many human activities. Raising livestock, for example, produces a lot of methane."
  },
  {
    "question": "What science is the study of matter and how it behaves?",
    "distractor3": "geology",
    "distractor1": "biology",
    "distractor2": "geneology",
    "correct_answer": "chemistry",
    "support": "Chemistry is the study of matter and how it behaves."
  },
  {
    "question": "When electrons from two atoms are each attracted to the nucleus of the other atom, what type of bond is formed?",
    "distractor3": "electrochemical bond",
    "distractor1": "hydrogen bond",
    "distractor2": "ionic bond",
    "correct_answer": "covalent bond",
    "support": "Covalent bonds form when the electron clouds of two atoms overlap with each other. In a simple H 2 molecule, the single electron in each atom becomes attracted to the nucleus of the other atom in the molecule as the atoms come closer together. Other covalent bonds form in the same way as unpaired electrons from two atoms “match up” to form the bond. In a fluorine atom, there is an unpaired electron in one of the 2p orbitals. When a F 2 molecule forms, the 2p orbitals from each of the two atoms overlap to produce the F−F covalent bond. The overlapping orbitals do not have to be of the same type to form a covalent bond. For example, in a molecule of HF, the 1s orbital of the hydrogen atom overlaps with the 2p orbital of the fluorine atom ( Figure below ):."
  },
  {
    "question": "In diffusion, substances tend to move from an area of high concentration to an area of what kind of concentration?",
    "distractor3": "Increase",
    "distractor1": "drop",
    "distractor2": "rise",
    "correct_answer": "low",
    "support": "Diffusion Diffusion is a passive process of transport. A single substance tends to move from an area of high concentration to an area of low concentration until the concentration is equal across a space. You are familiar with diffusion of substances through the air. For example, think about someone opening a bottle of ammonia in a room filled with people. The ammonia gas is at its highest concentration in the bottle; its lowest concentration is at the edges of the room. The ammonia vapor will diffuse, or spread away, from the bottle, and gradually, more and more people will smell the ammonia as it spreads. Materials move within the cell’s cytosol by diffusion, and certain materials move through the plasma membrane by diffusion (Figure 5.8). Diffusion expends no energy. On the contrary, concentration gradients are a form of potential energy, dissipated as the gradient is eliminated."
  },
  {
    "question": "What phase is pure chlorine present as?",
    "distractor3": "liquid",
    "distractor1": "oil/gas",
    "distractor2": "mist",
    "correct_answer": "gas",
    "support": ""
  },
  {
    "question": "Electronegativities are used to determine the polarity of covalent bonds. the polarity of a covalent bond can be judged by determining the difference of the electronegativities of what involved in the covalent bond?",
    "distractor3": "three atoms",
    "distractor1": "seven atoms",
    "distractor2": "six atoms",
    "correct_answer": "two atoms",
    "support": "Electronegativities are used to determine the polarity of covalent bonds. The polarity of a covalent bond can be judged by determining the difference of the electronegativities of the two atoms involved in the covalent bond, as summarized in the following table: Electronegativity Difference."
  },
  {
    "question": "What are the cell walls of fungi made of?",
    "distractor3": "casein",
    "distractor1": "lectin",
    "distractor2": "proteins",
    "correct_answer": "chitin",
    "support": "The cell walls of fungi are made of chitin. Chitin is a tough carbohydrate that also makes up the outer skeleton of insects. The cell walls of plants are made of cellulose."
  },
  {
    "question": "Rubber is what kind of solid?",
    "distractor3": "porous",
    "distractor1": "inorganic",
    "distractor2": "aqueous",
    "correct_answer": "amorphous",
    "support": "When a tire goes flat, its shape changes. The tire might be flat because of a slow leak in the tire valve. It could be flat because it ran over a nail or screw and ended up with a small hole where the air can leak out over a period of time. Or it could go flat when it hits a large rock or other object while travelling at high speeds (this one is for those readers who enjoy detective movies or TV shows). What if a crystalline solid like LiBr were ever made into a tire (now there’s a weird idea)? When it encountered a blow, the crystal would break into small pieces. Since rubber is an amorphous solid, it has a very different set of physical properties."
  },
  {
    "question": "Total internal reflections the princicple behind what type of optics?",
    "distractor3": "Blindness",
    "distractor1": "pipes optics",
    "distractor2": "refined optics",
    "correct_answer": "fiber optics",
    "support": "Total internal reflection is the principle behind fiber optics . A bundle of fibers made out of glass or plastic only a few micrometers in diameter is called a light pipe since light can be transmitted along it with almost no loss. Light passing down the fibers makes glancing collisions with the walls so that total internal reflection occurs."
  },
  {
    "question": "The rising and sinking of warm and cooler material is called what?",
    "distractor3": "depression",
    "distractor1": "diffusion",
    "distractor2": "insulation",
    "correct_answer": "convection",
    "support": "Hot lower mantle material rises upwards ( Figure below ). As it rises, it cools. At the top of the mantle it moves horizontally. Over time it becomes cool and dense enough that it sinks. Back at the bottom of the mantle, it travels horizontally. Eventually the material gets to the location where warm mantle material is rising. The rising and sinking of warm and cooler material is convection. The motion described creates a convection cell."
  },
  {
    "question": "Found in many electric devices, what is a coil of wire wrapped around a bar of iron or other ferromagnetic material?",
    "distractor3": "actuator",
    "distractor1": "battery",
    "distractor2": "superconductor",
    "correct_answer": "electromagnet",
    "support": "The animal mole is very different than the counting unit of the mole. Chemists nonetheless have adopted the mole as their unofficial mascot. National Mole Day is a celebration of chemistry that occurs on October 23rd (10/23) of each year."
  },
  {
    "question": "If more coils are added to an electromagnet it becomes?",
    "distractor3": "brighter",
    "distractor1": "lighter",
    "distractor2": "weaker",
    "correct_answer": "stronger",
    "support": "The combined magnetic force of the magnetized wire coil and iron bar makes an electromagnet very strong. In fact, electromagnets are the strongest magnets made. An electromagnet is stronger if there are more turns in the coil of wire or there is more current flowing through it. A bigger bar or one made of material that is easier to magnetize also increases an electromagnet’s strength. At the following URL, you can see an animation demonstrating how these factors affect the strength of an electromagnet. http://www. schoolphysics. co. uk/animations/Electromagnet/index. html."
  },
  {
    "question": "What is calculated by dividing the mass by the volume of a certain object?",
    "distractor3": "median",
    "distractor1": "radius",
    "distractor2": "diameter",
    "correct_answer": "density",
    "support": "The density of a certain object is calculated by dividing the mass by the volume. Suppose that a mass of 37.46 g is divided by a volume of 12.7 cm 3 . The result on a calculator would be:."
  },
  {
    "question": "Manganin is made up of metals that include copper, manganese and nickel - what do you generally call a metal of this type?",
    "distractor3": "mixed metal",
    "distractor1": "complex metal",
    "distractor2": "silicon",
    "correct_answer": "alloy",
    "support": "for metals, meaning their resistivity increases with temperature. Some alloys have been developed specifically to have a small temperature dependence. Manganin (which is made of copper, manganese and nickel), for example, has α close to zero (to three digits on the scale in Table 20.2), and so its resistivity varies only slightly with temperature. This is useful for making a temperature-independent resistance standard, for example."
  },
  {
    "question": "The particles in a colloid are large enough to scatter light, a phenomenon called what?",
    "distractor3": "bowman effect",
    "distractor1": "astral effect",
    "distractor2": "jonah effect",
    "correct_answer": "tyndall effect",
    "support": "The particles in a colloid are large enough to scatter light, a phenomenon called the Tyndall effect. This can make colloidal mixtures appear cloudy or opaque, such as the searchlight beams shown in Figure 11.31. Clouds are colloidal mixtures. They are composed of water droplets that are much larger than molecules, but that are small enough that they do not settle out."
  },
  {
    "question": "What is an organic compound that is the primary component of natural gas?",
    "distractor3": "sulfur",
    "distractor1": "ethanol",
    "distractor2": "magnesium",
    "correct_answer": "methane",
    "support": "Methane is an organic compound that is the primary component of natural gas. Its structure consists of a central carbon atom with four single bonds to hydrogen atoms (see Figure below ). In order to maximize their distance from one another, the four groups of bonding electrons do not lie in the same plane. Instead, each of the hydrogen atoms lies at the corners of a geometrical shape called a tetrahedron. The carbon atom is at the center of the tetrahedron. Each face of a tetrahedron is an equilateral triangle."
  },
  {
    "question": "Because the current is alternating, the magnetic field of the iron core keeps doing what?",
    "distractor3": "decreasing",
    "distractor1": "increasing",
    "distractor2": "changing",
    "correct_answer": "reversing",
    "support": "The transformer in the diagram consists of two wire coils wrapped around an iron core. Each coil is part of a different circuit. When alternating current passes through coil P, it magnetizes the iron core. Because the current is alternating, the magnetic field of the iron core keeps reversing. This is where electromagnetic induction comes in. The changing magnetic field induces alternating current in coil S of the other circuit."
  },
  {
    "question": "Batteries containing a liquid electrolyte, like those in cars, are referred to as what kind of battery?",
    "distractor3": "lithium cell",
    "distractor1": "time cell",
    "distractor2": "sand cell",
    "correct_answer": "wet cell",
    "support": "The car battery is an example of a “wet cell” battery, because there is a liquid electrolyte (sulfuric acid) present in the system. These batteries must operate in an upright position so the liquid material does not spill out. In contrast, dry cell batteries contain a paste that serves as the positive electrode. The composition and voltage depends on the specific battery, but typical voltage outputs are in the 1.0-1.5 volt range."
  },
  {
    "question": "What type of power is generated via underground sources of heat?",
    "distractor3": "solar",
    "distractor1": "hydrothermal",
    "distractor2": "volcanic",
    "correct_answer": "geothermal",
    "support": "Geothermal energy is an excellent resource in some parts of the world. Iceland is gets about one fourth of its electricity from geothermal sources. In the United States, California leads all states in producing geothermal energy. Geothermal energy in California is concentrated in the northern part of the state. The largest plant is in the Geysers Geothermal Resource Area. Geothermal energy is not economical everywhere. Many parts of the world do not have underground sources of heat that are close enough to the surface for building geothermal power plants."
  },
  {
    "question": "Solid coal, liquid petroleum, and liquid natural gas are all types of what?",
    "distractor3": "solar electric",
    "distractor1": "nuclear fusion",
    "distractor2": "hydroelectric",
    "correct_answer": "fossil fuels",
    "support": "Fossil fuels include solid coal, liquid petroleum, and liquid natural gas."
  },
  {
    "question": "A homogeneous mixture composed of two or more substances is called a what?",
    "distractor3": "structure",
    "distractor1": "mixture",
    "distractor2": "element",
    "correct_answer": "solution",
    "support": "Water is one of the most common ingredients in solutions. A solution is a homogeneous mixture composed of two or more substances. In a solution, one substance is dissolved in another substance, forming a mixture that has the same proportion of substances throughout. The dissolved substance in a solution is called the solute . The substance in which it is dissolved is called the solvent . An example of a solution in which water is the solvent is salt water. In this solution, a solid—sodium chloride—is the solute. In addition to a solid dissolved in a liquid, solutions can also form with solutes and solvents in other states of matter. Examples are given in the Table below ."
  },
  {
    "question": "Another interesting phenomenon associated with polarized light is the ability of some crystals to split an unpolarized beam of light into two. such crystals are said to be this?",
    "distractor3": "opaque matter",
    "distractor1": "reflective",
    "distractor2": "phosphorescent",
    "correct_answer": "birefringent",
    "support": "Another interesting phenomenon associated with polarized light is the ability of some crystals to split an unpolarized beam of light into two. Such crystals are said to be birefringent (see Figure 27.50). Each of the separated rays has a specific polarization. One behaves normally and is called the ordinary ray, whereas the other does not obey Snell’s law and is called the extraordinary ray. Birefringent crystals can be used to produce polarized beams from unpolarized light. Some birefringent materials preferentially absorb one of the polarizations. These materials are called dichroic and can produce polarization by this preferential absorption. This is fundamentally how polarizing filters and other polarizers work. The interested reader is invited to further pursue the numerous properties of materials related to polarization."
  },
  {
    "question": "What type of rocks form when magma cools and forms crystals?",
    "distractor3": "seismic",
    "distractor1": "sedimentary",
    "distractor2": "metarmorphic",
    "correct_answer": "igneous",
    "support": "Igneous rocks form when magma cools and forms crystals. These rocks can form at Earth’s surface or deep underground. Figure below shows a landscape in California’s Sierra Nevada that consists entirely of granite."
  },
  {
    "question": "What is the mass that is \"lost\" in fission or fusion actually converted to?",
    "distractor3": "hydrogen",
    "distractor1": "momentum",
    "distractor2": "pressure",
    "correct_answer": "energy",
    "support": "When the nucleus of a radioisotope undergoes fission or fusion, it loses a tiny amount of mass. What happens to the lost mass? It isn’t really lost at all. It is converted to energy. How much energy? . The change in mass is tiny, but it results in a great deal of energy."
  },
  {
    "question": "What kind of energy conversion is done by a fuel cell?",
    "distractor3": "electrical into nuclear",
    "distractor1": "wind into nuclear",
    "distractor2": "solar into chemical",
    "correct_answer": "chemical into electrical",
    "support": "Fuel Cells A fuel cell is a device that converts chemical energy into electrical energy. Fuel cells are similar to batteries but require a continuous source of fuel, often hydrogen. They will continue to produce electricity as long as fuel is available. Hydrogen fuel cells have been used to supply power for satellites, space capsules, automobiles, boats, and submarines (Figure 17.15)."
  },
  {
    "question": "What are natural sponges made of?",
    "distractor3": "sea shells",
    "distractor1": "sand",
    "distractor2": "sea plants",
    "correct_answer": "sea animals",
    "support": "Natural sponges, like the one in the picture above, are actually animals taken from the sea! The sponges in your home, however, were most likely never living things. Most sponges used in kitchens today are made from unnatural materials."
  },
  {
    "question": "What happens when iron is exposed to water and oxygen?",
    "distractor3": "combustion",
    "distractor1": "smoking",
    "distractor2": "shrinking",
    "correct_answer": "rusting",
    "support": "Corrosion involves the formation of an oxidized form of a metal by an electrochemical process. A common example is the rusting of iron when exposed to water and oxygen. The tarnishing of silver and the red or green deposits formed on copper are other examples. Corrosion in all its forms costs the U. S. millions of dollars each year in expenses for metal replacement."
  },
  {
    "question": "The binary halides are an important subclass of what?",
    "distractor3": "gases",
    "distractor1": "acids",
    "distractor2": "minerals",
    "correct_answer": "salts",
    "support": "Halides of the Representative Metals Thousands of salts of the representative metals have been prepared. The binary halides are an important subclass of salts. A salt is an ionic compound composed of cations and anions, other than hydroxide or oxide ions. In general, it is possible to prepare these salts from the metals or from oxides, hydroxides, or carbonates. We will illustrate the general types of reactions for preparing salts through reactions used to prepare binary halides. The binary compounds of a metal with the halogens are the halides. Most binary halides are ionic. However, mercury, the elements of group 13 with oxidation states of 3+, tin(IV), and lead(IV) form covalent binary halides. The direct reaction of a metal and a halogen produce the halide of the metal. Examples of these oxidation-reduction reactions include: Cd(s) + Cl 2(g) ⟶ CdCl 2(s) 2Ga(l) + 3Br 2(l) ⟶ 2GaBr 3(s)."
  },
  {
    "question": "What transition occurs as heat is added or removed from a substance?",
    "distractor3": "heat wave",
    "distractor1": "thermal reaction",
    "distractor2": "diffusion transition",
    "correct_answer": "phase transition",
    "support": "Phase transitions occur as heat is added or removed from a substance."
  },
  {
    "question": "What forms when one substance dissolves into another?",
    "distractor3": "solvent",
    "distractor1": "mixture",
    "distractor2": "compound",
    "correct_answer": "solution",
    "support": "When one substance dissolves into another, a solution is formed. A solution is a homogeneous mixture consisting of a solute dissolved into a solvent . The solute is the substance that is being dissolved, while the solvent is the dissolving medium. Solutions can be formed with many different types and forms of solutes and solvents."
  },
  {
    "question": "What kind of energy can move through glass much better than through paper?",
    "distractor3": "heat",
    "distractor1": "vibrational",
    "distractor2": "sound",
    "correct_answer": "light",
    "support": ""
  },
  {
    "question": "What are atoms of the same element but with different numbers of neutrons called?",
    "distractor3": "electrons",
    "distractor1": "variations",
    "distractor2": "masses",
    "correct_answer": "isotopes",
    "support": "Isotopes are atoms of the same element but with different numbers of neutrons."
  },
  {
    "question": "Amylose and amylopectin are the two most common components of naturally occurring what?",
    "distractor3": "chromosomes",
    "distractor1": "protein",
    "distractor2": "carbon",
    "correct_answer": "starch",
    "support": "Amylose and amylopectin are the two most common components of naturally occurring starch. Both consist of many glucose monomers connected into a polymer. Starch serves as energy storage in plants."
  },
  {
    "question": "What are the physical properties of water and carbon dioxide affected by?",
    "distractor3": "temperature",
    "distractor1": "weather",
    "distractor2": "weight",
    "correct_answer": "their polarities",
    "support": "The physical properties of water and carbon dioxide are affected by their polarities."
  },
  {
    "question": "Color, taste, and melting point are examples of what kind of properties?",
    "distractor3": "extensive properties",
    "distractor1": "experimental properties",
    "distractor2": "sensory properties",
    "correct_answer": "intensive properties",
    "support": "Intensive properties do not depend on the amount of the substance present. Some examples of intensive properties are color, taste, and melting point."
  },
  {
    "question": "Amorphous selenium is a photosensitive what?",
    "distractor3": "diffusion",
    "distractor1": "electromagnet",
    "distractor2": "insulator",
    "correct_answer": "semiconductor",
    "support": "Because amorphous selenium is a photosensitive semiconductor, exposing an electrostatically charged Se film to light causes the positive charge on the film to be discharged in all areas that are white in the original. Dark areas in the original block the light and generate an invisible, positively charged image. To produce an image on paper, negatively charged toner particles are attracted to the positive image, transferred to a negatively charged sheet of blank paper, and fused with the paper at high temperature to give a permanent image. The heaviest chalcogen, polonium, was isolated after an extraordinary effort by Marie Curie. (For more information on radioactivity and polonium, see Chapter 1 \"Introduction to Chemistry\", Section 1.5 \"The Atom\". ) Although she was never able to obtain macroscopic quantities of the element, which she named for her native country of Poland, she demonstrated that its chemistry required it to be assigned to group 16. Marie Curie was awarded a second Nobel Prize in Chemistry in 1911 for the discovery of radium and polonium."
  },
  {
    "question": "Reactive, high polarized substances made of carbon bonded to one carbon atom and one hydrogen atom are known as what?",
    "distractor3": "hydrocarbons",
    "distractor1": "proteins",
    "distractor2": "peptides",
    "correct_answer": "aldehydes",
    "support": "Aldehydes are commonly composed of a carbon bonded to one carbon atom and one hydrogen atom. Aldehydes are particularly reactive due to their high polarity, and are commonly associated with strong smells and tastes."
  },
  {
    "question": "The ability of a material to emit various wavelengths of light is similarly related to its?",
    "distractor3": "molar mass",
    "distractor1": "specific gravity",
    "distractor2": "half-life",
    "correct_answer": "atomic energy levels",
    "support": "Fluorescence and Phosphorescence The ability of a material to emit various wavelengths of light is similarly related to its atomic energy levels. Figure 30.31 shows a scorpion illuminated by a UV lamp, sometimes called a black light. Some rocks also glow in black light, the particular colors being a function of the rock’s mineral composition. Black lights are also used to make certain posters glow."
  },
  {
    "question": "What mineral is stored and is maintained at normal levels in blood by the skeletal system?",
    "distractor3": "magnesium",
    "distractor1": "potassium",
    "distractor2": "selenium",
    "correct_answer": "calcium",
    "support": "The skeletal system stores calcium and helps maintain normal levels of calcium in the blood. Bones take up and store calcium when blood levels of calcium are high. They release some of the stored calcium when blood levels of calcium are low."
  },
  {
    "question": "Over time, heavy metals build up in the tissues of organisms by what process?",
    "distractor3": "biosynthesis",
    "distractor1": "solidification",
    "distractor2": "oxygenation",
    "correct_answer": "bioaccumulation",
    "support": "Heavy metals, such as mercury and lead, are toxic to living things. They can enter food chains from the atmosphere. The metals build up in the tissues of organisms by bioaccumulation . Bioaccumulation is illustrated in Figure below . As heavy metals are passed up a food chain they accumulate. Imagine a low-level consumer eating a producer. That consumer takes in all of the heavy metals from all of the producers that it eats. Then a higher-level consumer eats it and accumulates all the heavy metals from all of the lower-level consumers that it eats. In this way, heavy metals may accumulate. At high levels in the food chain, the heavy metals may be quite become quite concentrated."
  },
  {
    "question": "What makes nobel gases unreactive?",
    "distractor3": "fusion",
    "distractor1": "chemical reaction",
    "distractor2": "magnetism",
    "correct_answer": "its electon configuration",
    "support": "The noble gases are unreactive because of their electron configurations. American chemist Gilbert Lewis (1875-1946) used this observation to explain the types of ions and molecules that are formed by other elements. He called his explanation the octet rule. The octet rule states that elements tend to form compounds in ways that give each atom eight valence electrons. An exception to this rule is the elements in the first period, which are particularly stable when they have two valence electrons. A broader statement that encompasses both the octet rule and this exception is that atoms react in order to achieve the same valence electron configuration as that of the nearest noble gas. Most noble gases have eight valence electrons, but because the first principal energy level can hold a maximum of two electrons, the first noble gas (helium) needs only two valence electrons to fill its outermost energy level. As a result, the nearby elements hydrogen, lithium, and beryllium tend to form stable compounds by achieving a total of two valence electrons."
  },
  {
    "question": "Larger molecules can have many, many of what that serve to keep the molecule together?",
    "distractor3": "connections",
    "distractor1": "arms",
    "distractor2": "tubes",
    "correct_answer": "bonds",
    "support": "Larger molecules can have many, many bonds that serve to keep the molecule together. In a large sample of a given molecular compound, all of the individual molecules are identical."
  },
  {
    "question": "What type of power is generated by splitting uranium atoms?",
    "distractor3": "fossil fuel power",
    "distractor1": "wind power",
    "distractor2": "solar power",
    "correct_answer": "nuclear power",
    "support": "Nuclear power plants use uranium that has been concentrated in fuel rods ( Figure below ). The uranium atoms are split apart when they are hit by other extremely tiny particles. These particles must be controlled or they would cause a dangerous explosion."
  },
  {
    "question": "Individual particles of a substance in what state are in fixed positions with respect to each other because there is not enough thermal energy to overcome the intermolecular interactions between the particles?",
    "distractor3": "structured",
    "distractor1": "stable",
    "distractor2": "undivided",
    "correct_answer": "solid",
    "support": "Solids In the solid state, the individual particles of a substance are in fixed positions with respect to each other because there is not enough thermal energy to overcome the intermolecular interactions between the particles. As a result, solids have a definite shape and volume. Most solids are hard, but some (like waxes) are relatively soft. Many solids composed of ions can also be quite brittle. Solids usually have their constituent particles arranged in a regular, three-dimensional array of alternating positive and negative ions called a crystal. The effect of this regular arrangement of particles is sometimes visible macroscopically, as shown in Figure 8.7 \"Crystalline Arrangement\". Some solids, especially those composed of large molecules, cannot easily organize their particles in such regular crystals and exist as amorphous (literally, “without form”) solids. Glass is one example of an amorphous solid."
  },
  {
    "question": "What type of covalent bond is a covalent bond in which the bonding electrons are shared equally between the two atoms?",
    "distractor3": "acidic",
    "distractor1": "ionic",
    "distractor2": "polar",
    "correct_answer": "nonpolar",
    "support": "A bond in which the electronegativity difference is less than 1.7 is considered to be mostly covalent in character. However, at this point we need to distinguish between two general types of covalent bonds. A nonpolar covalent bond is a covalent bond in which the bonding electrons are shared equally between the two atoms. In a nonpolar covalent bond, the distribution of electrical charge is balanced between the two atoms."
  },
  {
    "question": "What are organic molecules that consist of carbon, hydrogen, and oxygen called?",
    "distractor3": "proteins",
    "distractor1": "electrolytes",
    "distractor2": "amino acids",
    "correct_answer": "carbohydrates",
    "support": "Carbohydrates are organic molecules that consist of carbon, hydrogen, and oxygen. They are made up of repeating units called saccharides. They provide cells with energy, store energy, and form structural tissues."
  },
  {
    "question": "Cooling a mixture of equal parts nitric oxide and nitrogen dioxide to −21 °c produces what?",
    "distractor3": "carbon trioxide",
    "distractor1": "nitrate trioxide",
    "distractor2": "chloride trioxide",
    "correct_answer": "dinitrogen trioxide",
    "support": "Cooling a mixture of equal parts nitric oxide and nitrogen dioxide to −21 °C produces dinitrogen trioxide, a blue liquid consisting of N2O3 molecules (shown in Figure 18.35). Dinitrogen trioxide exists only in the liquid and solid states. When heated, it reverts to a mixture of NO and NO2."
  },
  {
    "question": "What converters are used on motor vehicles to break down pollutants in exhaust to non-toxic compounds?",
    "distractor3": "solvent converters",
    "distractor1": "back converters",
    "distractor2": "outer converters",
    "correct_answer": "catalytic converters",
    "support": "Catalytic converters are used on motor vehicles. They break down pollutants in exhaust to non-toxic compounds. For example, they change nitrogen oxides to harmless nitrogen and oxygen gasses."
  },
  {
    "question": "What are collisions between gas particles and container walls called?",
    "distractor3": "utilize collisions",
    "distractor1": "tubes collisions",
    "distractor2": "kinetic theory",
    "correct_answer": "elastic collisions",
    "support": "Collisions between gas particles and between particles and the container walls are elastic collisions."
  },
  {
    "question": "What is released during dehydration synthesis?",
    "distractor3": "photons",
    "distractor1": "helium",
    "distractor2": "air",
    "correct_answer": "water",
    "support": "Dehydration Synthesis Most macromolecules are made from single subunits, or building blocks, called monomers. The monomers combine with each other using covalent bonds to form larger molecules known as polymers. In doing so, monomers release water molecules as byproducts. This type of reaction is known as dehydration synthesis, which means “to put together while losing water."
  },
  {
    "question": "What term describes the energy required to increase the surface area of a liquid by a given amount?",
    "distractor3": "boiling point",
    "distractor1": "elastic collision",
    "distractor2": "viscosity",
    "correct_answer": "surface tension",
    "support": "Summary Surface tension is the energy required to increase the surface area of a liquid by a given amount. The stronger the intermolecular interactions, the greater the surface tension. Surfactants are molecules, such as soaps and detergents, that reduce the surface tension of polar liquids like water. Capillary action is the phenomenon in which liquids rise up into a narrow tube called a capillary. It results whencohesive forces, the intermolecular forces in the liquid, are weaker thanadhesive forces, the attraction between a liquid and the surface of the capillary. The shape of the meniscus, the upper surface of a liquid in a tube, also reflects the balance between adhesive and cohesive forces. The viscosity of a liquid is its resistance to flow. Liquids that have strong intermolecular forces tend to have high viscosities."
  },
  {
    "question": "What has large crystals because the magma began to cool slowly, then erupted?",
    "distractor3": "crystalline",
    "distractor1": "lava",
    "distractor2": "chalky",
    "correct_answer": "porphyry",
    "support": "This sarcophagus is housed at the Vatican Museum. The rock is the igneous extrusive rock porphyry. Porphyry has large crystals because the magma began to cool slowly, then erupted."
  },
  {
    "question": "What is the term for a homogeneous mixture of two or more substances?",
    "distractor3": "compound",
    "distractor1": "element",
    "distractor2": "saturation",
    "correct_answer": "solution",
    "support": "When rocks or other substances dissolve in water, they form a solution. A solution is a homogeneous mixture of two or more substances. The particles of a solution are mixed evenly throughout it. The particles are too small to be seen or to settle out. An example of a solution is salt water."
  },
  {
    "question": "Because water expands when it freezes, what property of water is lower when it is in a solid state than a liquid?",
    "distractor3": "salinity",
    "distractor1": "mass",
    "distractor2": "volume",
    "correct_answer": "density",
    "support": "The melting point of water is 0°C. Below this temperature, water is a solid (ice). Unlike most chemical substances, water in a solid state has a lower density than water in a liquid state. This is because water expands when it freezes. Again, hydrogen bonding is the reason. Hydrogen bonds cause water molecules to line up less efficiently in ice than in liquid water. As a result, water molecules are spaced farther apart in ice, giving ice a lower density than liquid water. A substance with lower density floats on a substance with higher density. This explains why ice floats on liquid water, whereas many other solids sink to the bottom of liquid water."
  },
  {
    "question": "At what temperatures do crystals formed by covalent molecular solids melt at?",
    "distractor3": "high",
    "distractor1": "hot",
    "distractor2": "scorching",
    "correct_answer": "low",
    "support": "Physical Properties of Ionic and Covalent Compounds In general, ionic and covalent compounds have different physical properties. Ionic compounds usually form hard crystalline solids that melt at rather high temperatures and are very resistant to evaporation. These properties stem from the characteristic internal structure of an ionic solid, illustrated schematically in part (a) in Figure 2.8 \"Interactions in Ionic and Covalent Solids\", which shows the three-dimensional array of alternating positive and negative ions held together by strong electrostatic attractions. In contrast, as shown in part (b) in Figure 2.8 \"Interactions in Ionic and Covalent Solids\", most covalent compounds consist of discrete molecules held together by comparatively weak intermolecular forces (the forces between molecules), even though the atoms within each molecule are held together by strong intramolecularcovalent bonds (the forces within the molecule). Covalent substances can be gases, liquids, or solids at room temperature and pressure, depending on the strength of the intermolecular interactions. Covalent molecular solids tend to form soft crystals that melt at rather low temperatures and evaporate relatively easily."
  },
  {
    "question": "What's the name for an organic compound in which halogen atoms are substituted for hydrogen in a hydrocarbon?",
    "distractor3": "alcohol",
    "distractor1": "sodium halide",
    "distractor2": "glucose",
    "correct_answer": "alkyl halide",
    "support": "An alkyl halide is an organic compound in which one or more halogen atoms are substituted for one or more hydrogen atoms in a hydrocarbon. The general formulas for organic molecules with functional groups use the letter R to stand for the rest of the molecule outside of the functional group. Because there are four possible halogen atoms (fluorine, chlorine, bromine, or iodine) that can act as the functional group, we use the general formula R−X to represent an alkyl halide. The rules for naming simple alkyl halides are listed below."
  },
  {
    "question": "Increasing the surface area of solid reactants increases what rate?",
    "distractor3": "breathing",
    "distractor1": "fusion",
    "distractor2": "metabolism",
    "correct_answer": "reaction",
    "support": "When a solid substance is involved in a chemical reaction, only the matter at the surface of the solid is exposed to other reactants. If a solid has more surface area, more of it is exposed and able to react. Therefore, increasing the surface area of solid reactants increases the reaction rate. Look at the hammer and nails pictured in the Figure below . Both are made of iron and will rust when the iron combines with oxygen in the air. However, the nails have a greater surface area, so they will rust faster."
  },
  {
    "question": "Organic acids such as acetic acid all contain a functional group called what?",
    "distractor3": "ester group",
    "distractor1": "glycoprotein group",
    "distractor2": "protein",
    "correct_answer": "carboxyl group",
    "support": "Organic acids such as acetic acid all contain a functional group called a carboxyl group ."
  },
  {
    "question": "What fuels are mixtures of hydrocarbons (compounds containing only hydrogen and carbon) that formed over millions of years from the remains of dead organisms?",
    "distractor3": "trilobites",
    "distractor1": "coal",
    "distractor2": "sediment",
    "correct_answer": "fossil",
    "support": "Oil, or petroleum, is one of several fossil fuels . Fossil fuels are mixtures of hydrocarbons (compounds containing only hydrogen and carbon) that formed over millions of years from the remains of dead organisms. In addition to oil, they include coal and natural gas. Fossil fuels provide most of the energy used in the world today. They are burned in power plants to produce electrical energy, and they also fuel cars, heat homes, and supply energy for many other purposes. You can see some ways they are used in the Figure below . For a more detailed introduction to fossil fuels, go to this URL: http://www. ecokids. ca/pub/eco_info/topics/energy/ecostats/index. cfm."
  },
  {
    "question": "What property is a property that depends on the amount of matter in a sample?",
    "distractor3": "non-exact",
    "distractor1": "provided",
    "distractor2": "relative",
    "correct_answer": "extensive",
    "support": "Some properties of matter depend on the size of the sample, while some do not. An extensive property is a property that depends on the amount of matter in a sample. The mass of an object is a measure of the amount of matter that an object contains. A small sample of a certain type of matter will have a small mass, while a larger sample will have a greater mass. Another extensive property is volume . The volume of an object is a measure of the space that is occupied by that object."
  },
  {
    "question": "Some products contain iron filings that will react with air to release what type of energy?",
    "distractor3": "spectral",
    "distractor1": "physical",
    "distractor2": "mechanical",
    "correct_answer": "thermal",
    "support": "Hikers, campers, and other outdoor folks take advantage of chemical reactions to keep their hands warm. Small containers of chemicals can undergo reaction to generate heat that can be used to avoid frostbite. Some products contain iron filings that will react with air to release thermal energy. These types of warmer cannot be reused. Other systems rely on heat being released when certain chemicals crystallize. If the warmer is placed in very hot water after use, the system can be regenerated."
  },
  {
    "question": "An extensive property is a property that depends on the amount of what in a sample?",
    "distractor3": "water",
    "distractor1": "plasma",
    "distractor2": "space",
    "correct_answer": "matter",
    "support": "An extensive property is a property that depends on the amount of matter in a sample."
  },
  {
    "question": "The exchange of heat stops once what property of equilibrium between the pan and the water is achieved?",
    "distractor3": "motion",
    "distractor1": "density",
    "distractor2": "viscosity",
    "correct_answer": "thermal",
    "support": "of 150ºC . Assume that the pan is placed on an insulated pad and that a negligible amount of water boils off. What is the temperature when the water and pan reach thermal equilibrium a short time later? Strategy The pan is placed on an insulated pad so that little heat transfer occurs with the surroundings. Originally the pan and water are not in thermal equilibrium: the pan is at a higher temperature than the water. Heat transfer then restores thermal equilibrium once the water and pan are in contact. Because heat transfer between the pan and water takes place rapidly, the mass of evaporated water is negligible and the magnitude of the heat lost by the pan is equal to the heat gained by the water. The exchange of heat stops once a thermal equilibrium between the pan and the water is achieved. The heat exchange can be written as ∣ Q hot ∣ = Q cold ."
  },
  {
    "question": "If the area to which a force is applied is smaller then the pressure will be?",
    "distractor3": "the same",
    "distractor1": "equal",
    "distractor2": "lower",
    "correct_answer": "greater",
    "support": "Pressure shows how concentrated the force is on a given area. The smaller the area to which force is applied, the greater the pressure is. Think about pressing a pushpin, like the one in the Figure below , into a bulletin board. You apply force with your thumb to the broad head of the pushpin. However, the force that the pushpin applies to the bulletin board acts only over the tiny point of the pin. This is a much smaller area, so the pressure the point applies to the bulletin board is much greater than the pressure you apply with your thumb. As a result, the pin penetrates the bulletin board with ease."
  },
  {
    "question": "Oxides contain one or two metal elements combined with what?",
    "distractor3": "ethanol",
    "distractor1": "nitrogen",
    "distractor2": "carbon",
    "correct_answer": "oxygen",
    "support": "Earth’s crust contains a lot of oxygen. The oxygen combines with many other elements to create oxide minerals. Oxides contain one or two metal elements combined with oxygen. Oxides are different from silicates because they do not contain silicon. Many important metals are found as oxides. For example, hematite and magnetite are both oxides that contain iron. Hematite (Fe 2 O 3 ) has a ratio of two iron atoms to three oxygen atoms. Magnetite (Fe 3 O 4 ) has a ratio of three iron atoms to four oxygen atoms. Notice that the word “magnetite” contains the word “magnet”. Magnetite is a magnetic mineral."
  },
  {
    "question": "What are the simplest type of carbon-based compounds?",
    "distractor3": "fossil fuels",
    "distractor1": "organic compounds",
    "distractor2": "inorganic compounds",
    "correct_answer": "hydrocarbons",
    "support": "Hydrocarbons are compounds that contain only carbon and hydrogen. Hydrocarbons are the simplest type of carbon-based compounds, but they can vary greatly in size. The smallest hydrocarbons have just one or two carbon atoms. The largest hydrocarbons may have thousands of carbon atoms."
  },
  {
    "question": "Which kind of rocks contain felsic minerals, typically contain aluminum and sodium and are high in silica?",
    "distractor3": "sedimentary",
    "distractor1": "metamorphic",
    "distractor2": "igneous",
    "correct_answer": "felsic igneous",
    "support": "Felsic igneous rocks contain felsic minerals. They typically contain aluminum and sodium; they are high in silica. Quartz and potassium feldspar are felsic minerals. Minerals and rocks with a composition in between mafic and felsic are called intermediate."
  },
  {
    "question": "At what temperatures do alkanes with more carbon atoms boil?",
    "distractor3": "farther temperatures",
    "distractor1": "heavier temperatures",
    "distractor2": "lower temperatures",
    "correct_answer": "higher temperatures",
    "support": "Saturated hydrocarbons are given the general name of alkanes . The name of specific alkanes always ends in – ane . The first part of the name indicates how many carbon atoms each molecule of the alkane has. The smallest alkane is methane. It has just one carbon atom. The next largest is ethane with two carbon atoms. The chemical formulas and properties of methane, ethane, and other small alkanes are listed in the Table below . The boiling and melting points of alkanes are determined mainly by the number of carbon atoms they have. Alkanes with more carbon atoms generally boil and melt at higher temperatures."
  },
  {
    "question": "One common way to remove phosphates from water is by the addition of what?",
    "distractor3": "isotopes",
    "distractor1": "acetic acid",
    "distractor2": "nitrous oxide",
    "correct_answer": "calcium hydroxide",
    "support": "One common way to remove phosphates from water is by the addition of calcium hydroxide, known as lime, Ca(OH)2. The lime is converted into calcium carbonate, a strong base, in the water. As the water is made more basic, the calcium ions react with phosphate ions to produce hydroxylapatite, Ca5(PO4)3(OH), which then precipitates out of the solution:."
  },
  {
    "question": "Carbon can form single, double, or triple what with other carbon atoms",
    "distractor3": "electron bonds",
    "distractor1": "ionic bonds",
    "distractor2": "phenotype bonds",
    "correct_answer": "covalent bonds",
    "support": "Carbon can form single, double, or triple covalent bonds with other carbon atoms."
  },
  {
    "question": "What are solid-solid solutions like brass and bronze called?",
    "distractor3": "amalgams",
    "distractor1": "oxides",
    "distractor2": "mixtures",
    "correct_answer": "alloys",
    "support": "Solid-solid solutions such as brass, bronze, and sterling silver are called alloys. Bronze (composed mainly of copper with added tin) was widely used in making weapons in times past dating back to at least 2400 B. C. This metal alloy was hard and tough, but was eventually replaced by iron."
  },
  {
    "question": "What is the main element in organic compounds?",
    "distractor3": "hydrogen",
    "distractor1": "oxygen",
    "distractor2": "helium",
    "correct_answer": "carbon",
    "support": "A compound found mainly in living things is known as an organic compound . Organic compounds make up the cells and other structures of organisms and carry out life processes. Carbon is the main element in organic compounds, so carbon is essential to life on Earth. Without carbon, life as we know it could not exist."
  },
  {
    "question": "What are certain numbers of nucleons, known as magic numbers stable against?",
    "distractor3": "half-lifes",
    "distractor1": "water",
    "distractor2": "radiation",
    "correct_answer": "nuclear decay",
    "support": "certain numbers of nucleons, known as magic numbers, are stable against nuclear decay. These numbers of protons or neutrons (2, 8, 20, 28, 50, 82, and 126) make complete shells in the nucleus. These are similar in concept to the stable electron shells observed for the noble gases. Nuclei that have magic numbers of both protons and neutrons, such as 42 He, 168 O, 40 and 208 are called “double magic” and are particularly stable. These trends in 20 Ca, 82 Pb, nuclear stability may be rationalized by considering a quantum mechanical model of nuclear energy states analogous to that used to describe electronic states earlier in this textbook. The details of this model are beyond the scope of this chapter. Stable Nuclear Isotopes Number of Stable Isotopes."
  },
  {
    "question": "When small particles, such as clay and silt, are in mixed in water but do not disolve in the water, what state are they in?",
    "distractor3": "sedimentation",
    "distractor1": "mud",
    "distractor2": "incomplete",
    "correct_answer": "suspension",
    "support": "Small particles, such as clay and silt, are carried in suspension . They are mixed throughout the water. These particles are not dissolved in the water."
  },
  {
    "question": "When you burn wood into ash or burn a marshmallow to become brown and crispy, it is impossible to undo.  this change is known as what?",
    "distractor3": "physical change",
    "distractor1": "carbon change",
    "distractor2": "compounding change",
    "correct_answer": "chemical change",
    "support": "Yummy! S’mores are on the way! Did you ever toast marshmallows over a campfire? The sweet treats singe on the outside and melt on the inside. Both the fire and the toasted marshmallows are evidence of chemical changes. In the process of burning, the wood changes to ashes and gases, and the outside of the marshmallow turns brown and crispy. Neither the wood nor the marshmallows can change back to their original form. That’s because burning is a chemical change and chemical changes are often impossible to undo. In this unit, you’ll learn about many types of chemical changes, including how they occur and why you can’t live without them."
  },
  {
    "question": "Which element has the highest electronegativity value?",
    "distractor3": "Barium",
    "distractor1": "chlorine",
    "distractor2": "magnesium",
    "correct_answer": "fluorine",
    "support": "The highest electronegativity value is for fluorine."
  },
  {
    "question": "Each parapodium has numerous chaetae, bristles made of what?",
    "distractor3": "casein",
    "distractor1": "ricin",
    "distractor2": "lectin",
    "correct_answer": "chitin",
    "support": ""
  },
  {
    "question": "What do you call electrons that form bonds with other elements in compounds and generally determine the properties of elements?",
    "distractor3": "ionic electrons",
    "distractor1": "isotopes",
    "distractor2": "shell electrons",
    "correct_answer": "valence electrons",
    "support": "Other properties of the transition metals are unique. They are the only elements that may use electrons in the next to highest—as well as the highest—energy level as valence electrons. Valence electrons are the electrons that form bonds with other elements in compounds and that generally determine the properties of elements. Transition metals are unusual in having very similar properties even with different numbers of valence electrons. The transition metals also include the only elements that produce a magnetic field. Three of them have this property: iron (Fe), cobalt (Co), and nickel (Ni)."
  },
  {
    "question": "Silver chloride can be used as an antidote for which kind of poisoning?",
    "distractor3": "arsenic",
    "distractor1": "the bends",
    "distractor2": "carbon monoxide",
    "correct_answer": "mercury",
    "support": "Silver chloride is an important compound that is commonly used in the production of photographic film. It also has many other uses, such as an antidote for mercury poisoning, a component of pottery glazes, and a reference standard for electrochemistry setups. It can be produced according to the reaction shown above. Now we will practice use of mole ratios and stoichiometry to determine the amounts of products and reactants necessary in our reaction."
  },
  {
    "question": "What helps maglev trains go very fast?",
    "distractor3": "gravity",
    "distractor1": "rollers",
    "distractor2": "wheels",
    "correct_answer": "magnets",
    "support": "The futuristic-looking train in Figure below is called a maglev train. The word \"maglev\" stands for \"magnetic levitation. \" Magnets push the train upward so it hovers, or levitates, above the track without actually touching it. This eliminates most of the friction acting against the train when it moves. Other magnets pull the train forward along the track. Because of these magnets, the train can go very fast. It can fly over the countryside at speeds up to 480 kilometers (300 miles) per hour! What are magnets and how do they exert such force? In this lesson, you’ll find out."
  },
  {
    "question": "Sulfuric acid conducts the charge in what kind of battery?",
    "distractor3": "lithium ion",
    "distractor1": "nickel-metal hydride",
    "distractor2": "nickel cadmium",
    "correct_answer": "lead-acid cell",
    "support": "Figure 21.10 Artist’s conception of a lead-acid cell. Chemical reactions in a lead-acid cell separate charge, sending negative charge to the anode, which is connected to the lead plates. The lead oxide plates are connected to the positive or cathode terminal of the cell. Sulfuric acid conducts the charge as well as participating in the chemical reaction."
  },
  {
    "question": "Compared to a straight wire, a coiled wire has a stronger what?",
    "distractor3": "gravitational field",
    "distractor1": "horizontal field",
    "distractor2": "proximate field",
    "correct_answer": "magnetic field",
    "support": "Any wire with current flowing through it has a magnetic field. However, the magnetic field around a coiled wire is stronger than the magnetic field around a straight wire. That’s because each turn of the wire in the coil has its own magnetic field. Adding more turns to the coil of wire increases the strength of the field. Increasing the amount of current flowing through the coil also increases the strength of the magnetic field."
  },
  {
    "question": "Ground collapse, associated with chambers of what substance, leads to formation of a caldera?",
    "distractor3": "lava",
    "distractor1": "molten",
    "distractor2": "stone",
    "correct_answer": "magma",
    "support": "The cause of supervolcano eruptions is being debated. Enormous magma chambers are filled with super hot magma. This enormous eruption leaves a huge hole. The ground collapses and creates a caldera."
  },
  {
    "question": "The extrusive type of what rock cools rapidly from lava at the surface?",
    "distractor3": "erythematous",
    "distractor1": "crystalline",
    "distractor2": "precipitous",
    "correct_answer": "igneous",
    "support": "Extrusive igneous rocks cool from lava rapidly at the surface. They have small crystals."
  },
  {
    "question": "Which construction material previously used in factories and in homes caused cancer?",
    "distractor3": "Paints contains lead",
    "distractor1": "Silica",
    "distractor2": "Alkylphenols",
    "correct_answer": "asbestos",
    "support": "The past use of asbestos in factories and in homes. Asbestos is a very dangerous material, and it was used in many buildings ( Figure below ). Asbestos can cause cancer and other lung diseases. The use of asbestos is not allowed today."
  }
]