Chemistry Radiation – Flashcards

Chapter 7 The half-life of carbon-14 is 5,730 years. If you started with 100.0 g of carbon-14, how much would remain after 4 half-lives? A. 25.0 g B. 12.5 g C. 6.25 g D. 57.3 g

Which naturally occurring type of radiation has the greatest penetrating power? A. alpha B. beta C. gamma D. neutron

Which naturally occurring radioactive particles are the size of a helium nucleus? A. alpha particles B. beta particles C. gamma radiation D. neutrons

Which naturally occurring radioactive particles are negatively charged? A. alpha particles B. beta particles C. gamma radiation D. neutrons

Which naturally occurring radioactive particles are the largest? A. alpha particles B. beta particles C. gamma radiation D. neutrons

What type of radiation is given off in this nuclear reaction? A. alpha B. beta C. gamma D. neutron

What type of radiation is given off in this nuclear reaction? A. alpha B. beta C. gamma D. neutron

If you have 200.0 g of radioisotope with a half-life of 5 days, how much isotope would remain after 15 days? A. 12.5 g B. 13.3 g C. 25.0 g D. 40.0 g

You have a radioisotope with a half-life of 5 days. How many days will it take before the radioisotope is completely gone? A. 5 days B. 50 days C. 500 days D. The isotope will never be completely gone.

Which would contribute most to your annual radiation exposure? A. living at an elevation 1,000 m above sea level B. having a dental X-ray C. living within 50 miles of a nuclear reactor D. smoking a pack and a half of cigarettes per day

In the famous equation E = mc2, the symbols represent: A. E = Einstein, m = matter, c = speed of light B. E = energy, m = mass, c = characteristic of the particle C. E = Einstein, m = meters, c = conversion D. E = energy, m = mass, c = speed of light

Fission is the process of creating energy by A. combining small nuclei to form a larger, more stable nucleus. B. combining small nuclei to form a larger, less stable nucleus. C. splitting large nuclei with bombarding protons. D. splitting large nuclei with bombarding neutrons.

Which is the balanced equation for the fission of U-235? A. B. C. D.

How much energy is created from the conversion of 1.0 10¯4 kg of matter? (speed of light = 3.0 108 m/s) A. 3.0 104 J B. 3.0 107 J C. 9.0 1012 J D. 9.0 1015 J

If 1.8 1014 J are given off in a nuclear reaction, how much matter was converted into energy? A. 2.0 10¯3 kg B. 7.2 102 kg C. 6.0 105 kg D. 1.6 1031 kg

Which is a common characteristic of both nuclear and conventional electric power plants? A. smoke stacks B. fuel rods C. water cooling systems D. turbines

Which feature or process is unique to nuclear power plants when compared to conventional coal-burning power plants? A. formation of steam B. smoke stacks C. generators D. control rods

Which of these is not a realistic risk associated with nuclear power plants? A. storage of spent fuel rods B. the likelihood of nuclear explosion C. a meltdown from loss of coolant D. thermal pollution of the coolant source

Which statement best summarizes why a nuclear power plant cannot explode like a nuclear bomb? A. Control rods are in place among the fuel rods in the reactor. B. The fuel concentration is too low to build the neutron stream required in an explosive chain reaction. C. A nuclear explosion requires a chain reaction. D. The reactor cooling system is equipped with safety devices.

Which is the best critique of the following statement? "Radioactivity is so dangerous that we should do all we can to completely eliminate our exposure." A. Absolutely correct. Radioactivity is the ultimate danger and we should keep our exposure to zero. B. Not true. We should not fear radioactivity because it is a natural part of life. C. Somewhat true. Radioactivity can be dangerous, but in some circumstances, exposure to it is unavoidable, so zero exposure is not a reasonable goal. D. Somewhat true. Although any exposure to radioactivity is potentially deadly, there is nothing we can do to avoid it so we must be resigned to the risk.

Which does not contribute to your annual radiation dose? A. the type of structure you live in B. the amount of time you spend riding in jet planes C. the number of dental X-rays you get each year D. the number of hours you spend listening to the radio

Which is true about radioactivity? Radioactivity A. is used to treat certain cancers. B. damages white blood cells. C. deforms DNA. D. All of these choices are true.

What is the maximum one-time dose of radiation one can receive without suffering any detectable physiological effects? A. 25 rem (0.25 Sv) B. 50 rem (0.5 Sv) C. 100 rem (1.0 Sv) D. 200 rem (2.0 Sv)

Which is not true of radioactive half-life? Radioactive half-life is A. the time required for the level of radioactivity in a sample to be cut in half. B. independent of the amount of radioactive material present. C. increased by heating the isotope. D. independent of the physical or chemical form of the isotope.

Which fact is not important when drawing conclusions from C-14 dating? A. Living organisms exchange carbon with the atmosphere. B. C-14 has a half-life of 5,730 years. C. Dead organisms do not exchange carbon with the atmosphere. D. C-14 emits beta particles

Which country gets the smallest percentage of its electrical power from nuclear reactors? A. Canada B. France C. Belgium D. Spain

Which best explains why the United States has the greatest number of nuclear reactors worldwide but one of the lower percentages of electricity produced by nuclear reactors? A. Most U.S. reactors are not operational. B. The United States uses more electrical power than most countries. C. U.S. officials believe that coal-powered plants are more efficient than nuclear power plants. D. Most U.S. reactors are more than 30 years old.

For safety reasons, high-level nuclear waste (HLW) must be contained A. for 10 years. B. for 100 years. C. until it becomes low-level nuclear waste. D. permanently.

Which is not a suitable option for the disposal of spent nuclear fuel? A. Seal it in deep pools. B. Monitor it in storage near the ground surface. C. Bury it deep within the Earth. D. Seal it in a landfill.

Which is a characteristic of "surface" high-level nuclear waste storage that is not a characteristic of storing the waste in a geological repository? Waste in a geological repository is not A. as easily accessible. B. feasible. C. secure. D. safe.

Most high-level nuclear waste in the United States is currently A. sealed deep within the Earth. B. encased in glass and buried near the surface. C. sealed in deep pools at the sites where it was produced. D. stored at breeder reactors waiting for reprocessing.

Which is the best critique of the statement: "Nuclear waste is nuclear waste. All nuclear waste is dangerous and should be handled with the same level of caution and disposed of in the same way." A. I do not want anything nuclear buried in my backyard or even in my state if possible. All nuclear waste is extremely dangerous and there is no way to know what awful things it could cause in the future. B. There are many kinds of nuclear waste and they are very different from one another. However the fact remains they are all natural and not to be feared. C. Nuclear waste can be classified as high-level or low-level depending upon the relative quantities of radioactive material. While it is true that one should be cautious with both types, the risks and precautions are much greater with HLW. D. Nuclear waste that is a problem is primarily produced by the military and they need to develop a safe way to dispose of this material. Non-military nuclear waste is not really a problem.

Which is not considered to be low-level radioactive waste? A. clothing for workers administering nuclear medicine B. smoke detectors C. spent fuel rods D. radioactive pharmaceuticals

Which is the biggest impediment to storing low-level radioactive waste? A. lack of proper barrels B. economic feasibility C. lack of proper technology D. political opposition

The fuel for both nuclear and coal power plants must be mined. Which miners are most likely to contract black lung disease? A. coal miners B. uranium miners C. plutonium miners D. Black lung is not a risk for miners of any fuel.

Thermal pollution is possible at water sources near A. coal-burning plants. B. nuclear plants. C. both coal-burning and nuclear plants. D. neither coal-burning nor nuclear plants.

Waste created at these power plants must be stored indefinitely: A. coal-burning plants. B. nuclear plants. C. both coal-burning and nuclear plants. D. neither coal-burning nor nuclear plants.

Smokestacks at these plants release sulfur oxides and carbon dioxide into the air: A. coal-burning plants. B. nuclear plants. C. both coal-burning and nuclear plants. D. neither coal-burning nor nuclear plants.

Including fuel production and power generation, which type of power plant is responsible for more fatalities annually? A. nuclear plants B. coal-burning plants C. Neither nuclear nor coal-burning plants may be connected to fatalities. D. Fatalities are substantially the same for both nuclear and coal-burning plants.

Which type of power plant releases more radioactive particles into the atmosphere annually? A. nuclear plants B. coal-burning plants C. Neither nuclear nor coal-burning plants release radioactivity into the atmosphere. D. The release of radioactivity at both nuclear and coal-burning plants is nearly the same.

Which is not a benefit associated with nuclear power plants? A. efficient production of electricity B. reduction of CO2 in the atmosphere C. inexpensive to operate D. helps reduce the levels of acid rain

Which is not a reason for the decline in the reliance on nuclear power for electricity generation in the United States over the last 30 years? A. a lack of available nuclear fuel B. the need for enhanced safety training for workers C. the need to retrofit old plants D. an increase in the required number of qualified personnel

Which factor will support the growth of nuclear energy in the future? A. smaller, more efficient reactor design B. a ban on the use and development of breeder reactors C. tax incentives for the oil and gas industry D. high cost of new, safer technology

Which factor will oppose the growth of nuclear energy in the future? A. standardization of reactor design B. increased operational lifetime of reactors C. shorter construction time for reactors D. transportation of high level waste to depositories

Which is the best critique of the statement: "Nuclear energy will save our atmosphere."? The statement is A. true, because nuclear power plants do not pollute the atmosphere. We should replace coal-burning plants with nuclear plants and we'd breathe easier. B. ridiculous, because there is no proof that our atmosphere needs saving. Why should we take on the nuclear waste disposal problem to solve a problem that does not exist? C. true, because nuclear power plants release fewer pollutants into the air than coal-burning plants. However, it is also false because we have no information indicating what percentage of coal-burning plants would have to be replaced with nuclear plants to make a significant difference. D. false, because it is not clear that there is an atmospheric problem. If there is a problem, it cannot be as bad as the potential danger of expanding the nuclear threat on this planet with more nuclear power plants.

What percentage of a radioactive isotope would remain after three half-lives? A. 6.3% B. 12.5% C. 25.0% D. 50.0%

The primary reason countries worldwide have turned to nuclear power for electricity generation is to reduce A. the greenhouse effect. B. acid rain. C. their reliance on fossil fuels. D. the damage caused by strip mining.

As compared to high-level nuclear waste, low-level nuclear waste A. has longer half-lives. B. is contaminated with smaller quantities of radioactive material. C. includes spent fuel rods. D. can be disposed of in landfills.

The annual radiation dose for most citizens of the United States is between A. 0 to 0.10 Sv. B. 0.10 to 0.25 Sv. C. 0.25 to 0.50 Sv. D. 0.50 to 1.0 Sv.

The greatest percentage of background radiation comes from A. nuclear power plants. B. medical X-rays. C. living things. D. naturally occurring radon.

Breeder reactors A. convert spent fuel rods into useful fuel. B. produce Pu-239, the radiation that cannot penetrate human skin. C. produce Pu-239, which can be used to build nuclear weapons. D. All of these choices are true.

Which is a known risk associated with nuclear power plants? A. The electricity produced will be radioactive. B. The water used to cool the system will become radioactive. C. The workers will have higher risks for cancer than the standard population. D. The cooling water source can suffer thermal pollution.

Approximately what percentage of the electrical energy generated in the United States is produced from nuclear energy? A. < 2% B. 10% C. 20% D. 50%

Which form of radiation has the highest Q factor? A. UV radiation B. alpha particles C. beta particles D. X-rays

The rad (radiation absorbed dose) is defined as the absorption of 0.01 J of radiant energy per kilogram (0.01 J/kg) of body weight. What is the radiation dose for a 50 kg woman exposed to 0.85 J of energy? A. 0.085 rad B. 0.017 rad C. 1.70 rad D. It depends on the radiation source.

Which radiation source is the biggest contributor to the average annual dose? A. home building materials B. food, air, and water C. a nuclear power plant within 50 miles D. fallout from nuclear weapons testing

Which type of power plant releases the greatest amount of radioactivity into the atmosphere? A. coal. B. nuclear fission C. hydroelectric D. natural gas

Which example is both a type of nuclear radiation and electromagnetic radiation? A. microwave radiation B. gamma radiation C. alpha rays D. ultraviolet radiation

Rank the forms of nuclear radiation according to mass. A. gamma, alpha, beta B. beta, gamma, alpha C. alpha, gamma, beta D. alpha, beta, gamma

In which organ does radioactive I-131 accumulate? A. liver B. pituitary gland C. thyroid gland D. adrenal glands

Which scientific law best applies to nuclear reactions? A. Conservation of Matter B. Conservation of Energy C. Conservation of Matter and Energy D. None of these choices is correct.

A breeder reactor produces which nuclear fuel? A. 239Pu B. 238U C. 141Ba D. 235U

Although the nuclear reactors used to produce electricity do not release carbon dioxide, nuclear energy is still responsible for the release of this greenhouse gas. Which activity probably does not contribute largely to the carbon dioxide released by nuclear power generation. A. mining and production of uranium fuel rods B. transportation of nuclear fuel and waste C. construction of the nuclear reactor facility D. cooling of the secondary coolant by a large reservoir of water

The radioactive decay series of 238U terminates at which nonradioactive isotope? A. 210Tl B. 210Bi C. 206Pb D. 144Ba

What is the most common radioactive element in our food? A. 23Mg B. 40K C. 131I D. 90Sr

CHAPTER 8

Chemical energy is converted directly into electrical energy in A. a battery. B. an electrical power plant. C. an electrolytic cell. D. an automobile's engine.

During the chemical reaction in an electrochemical cell, A. a substance is oxidized and gains control over electrons. B. electrons travel from the cathode to the anode. C. oxidation may take place without there also being reduction. D. oxidation occurs at the anode.

Which is an oxidation half-reaction? A. 2 H2 + O2 2 H2O B. Zn Zn2+ + 2 e¯ C. 2 HCl + Ba(OH)2 2 H2O + BaCl2 D. Cl2 + 2 e¯ 2 Cl¯

In a galvanic cell, A. oxidation takes place at the cathode. B. electrolytes are added to carry electrons between electrodes. C. oxidation and reduction take place at the same time at different electrodes. D. electrical energy is used to reverse spontaneous chemical reactions.

Whenever a substance is oxidized, A. it is called the oxidizing agent. B. some other substance must be reduced. C. it gains electrons. D. hydronium ions are produced.

The current through a wire is most closely related to the A. energy of the electrons flowing through the wire. B. type of electrons flowing through the wire. C. number of electrons flowing through the wire. D. mass of the electrons flowing through the wire.

Which is the cathode in this galvanic cell? A. the solid zinc electrode B. the Zn2+(aq) ions in the 1 M solution C. the solid silver electrode D. the Ag+(aq) ions in the 1 M solution

In an electrochemical cell, the anode is A. the electrode at which oxidation takes place. B. the material used to connect the two half cells to each other. C. always used up before the cathode. D. never a metal.

In this electrochemical cell, the reduction half reaction is A. Cu2+(aq) + 2 e¯ Cu(s) B. Zn(s) Zn2+(aq) + 2 e¯ C. Zn(s) Cu(s) D. Cu2+(aq) Zn2+(aq)

The opposite of a galvanic cell is A. a battery. B. an electrolytic cell. C. a fuel cell. D. a photovoltaic (solar) cell.

Which is not a necessary consideration for a battery designed to run a cell phone or portable MP3 player? A. It must develop a useful level of electrochemical potential. B. It must "run" for a reasonable amount of time. C. It must use liquid, aqueous solutions. D. It must be fairly light in weight.

What condition must be met for a battery to be rechargeable? A. Either its anode or its cathode must generate a gas as a result of the electrochemical reaction. B. It must generate electricity via an acid-base reaction rather than via an oxidation reduction reaction. C. The battery must be open to the outside so that it can vent any internal pressure that builds up from gases within it. D. The electrochemical reaction of the battery must be reversible.

What is the primary determinant of the voltage developed by a battery? A. the nature of the materials in the reaction B. the age of the battery C. the overall size of the galvanic cells D. the size of the electrodes

Very small mercury batteries have been made and used in a multitude of applications. Why have they been replaced by other kinds of batteries for most applications? A. Mercury has become far too expensive to use in batteries. B. Mercury is poisonous and difficult to dispose of. C. These batteries cannot generate enough current for any modern devices. D. Though they may be made very small, they are far too heavy to use in most applications.

Which type of widely used battery is not rechargeable? A. alkaline B. lithium-ion C. lead-acid (storage batteries) D. nickel-cadmium (NiCad)

Compare commercial electrical power plants, batteries, and solar cells in terms of their efficiencies in producing electrical energy. Rank them from least efficient to most efficient. A. solar cells, batteries, electrical power plants B. electrical power plants, solar cells, batteries C. batteries, solar cells, electrical power plants D. solar cells, electrical power plants, batteries

Why can the lead-acid batteries used in cars generate electricity for several years before running down? A. A lead-acid battery is so large that it holds large quantities of the chemicals whose electrochemical interaction creates the electricity. B. The mechanical motion of the engine drives an alternator that generates electricity to recharge the battery. C. These batteries are used only to generate the electricity that makes the first spark plug "spark." Therefore, they are hardly used at all when a car is started, and never when it is driven. D. The electrons they generate, not the chemical components, provide almost all of the electricity.

Which type of battery is widely used to store the excess energy generated by windmill farms and solar panels? A. alkaline B. lithium ion C. lead acid D. nickel-metal hydride

Which type of battery is best for use in heart (cardiac) pacemakers? A. alkaline B. lithium-iodine C. mercury D. nickel-cadmium

In a fuel cell, A. there is oxidation, but no reduction. B. reduction takes place at the cathode. C. there is direct conversion of mechanical energy into electricity. D. a chemical reaction produces heat, which then produces electricity.

A major advantage of a fuel cell over a standard battery is that A. as long as oxygen and fuel are supplied, a fuel cell will not "run down" like a battery will. B. a fuel cell generates electricity without the need for an oxidation-reduction reaction. C. a fuel cell is 100% efficient at generating electricity, whereas a battery is less than 1% efficient. D. as it generates electricity, a fuel cell produces more fuel than it uses.

Which is not a component of a fuel cell? A. a timer B. an anode C. a cathode D. an electrolyte

Which is not an advantage of using a solid electrolyte in a fuel cell? A. It is impermeable to liquids and gases and will keep the fuel and oxidizer separated. B. It cannot "dry out" and will allow the fuel cell to operate at higher temperatures than one that uses water as part of the proton transfer mechanism. C. It may use various fuels other than hydrogen gas, the fuel of choice in systems using water as part of the proton transfer mechanism. D. It eliminates the need for an oxidant; only a fuel is required.

How does using hydrogen as the fuel in an electric power plant compare with using hydrogen as the fuel in a fuel cell? A. H2 used as a fuel in a power plant must be more pure than the H2 used in a fuel cell. B. Burning H2 in a power plant produces many more pollutants than using H2 in a fuel cell. C. A fuel cell using hydrogen operates at a higher overall efficiency than would a power plant burning hydrogen as a fuel. D. Using H2 in a fuel cell generates far more heat than burning it in a power plant.

Which is not a current or planned use for the electricity generated by fuel cells? A. as the output of small power plants B. to operate space shuttles C. to control nuclear fusion D. to power a cell phone

As fuel cells become more widely accepted and are used more, we will A. become less dependent on electrical energy. B. become progressively more dependent on fossil fuels and progressively less dependent on renewable resources for power generation. C. be able to generate electricity in places where we cannot now do so. D. eventually deplete our stores of coal as a source of hydrogen.

How does the reaction of hydrogen and oxygen to produce energy in a fuel cell differ from their interaction during the direct combustion of hydrogen and oxygen? A. The direct combustion of hydrogen and oxygen produces several different products, whereas the fuel cell produces only water. B. Much less heat energy is produced in a fuel cell than via direct combustion of hydrogen and oxygen. C. In the fuel cell, there is an oxidation-reduction reaction between hydrogen and oxygen. In the direct combustion of hydrogen and oxygen, there is no such reaction. D. It is much easier to control the hydrogen and oxygen during direct combustion than during their reaction in a fuel cell.

What is the purpose of the hot KOH solution in the fuel cell? A. It is the product of the reaction between the hydrogen, the oxygen, and the electrodes. B. It is used to dissipate the heat produced by the operation of the fuel cell. C. It is part of the acid-base reaction that generates the electricity in most fuel cells. D. It maintains electroneutrality as it transfers ions between the half cells where the hydrogen and oxygen react.

A fuel cell does not "run down" like a standard battery because A. the reactants in a battery must be stored inside the battery, whereas the reactants for a fuel cell flow in as needed. B. a fuel cell continually recycles the same electrons, whereas a battery must continually generate new ones. C. a battery is completely dependent upon oxidation-reduction reactions, whereas a fuel cell depends on acid-base reactions. D. a battery has many moving parts, whereas a fuel cell has none.

In general, a modern hybrid vehicle is less polluting than a standard vehicle because it runs on both a A. gasoline engine and an electric motor run by a rechargeable battery. B. gasoline engine and a fuel cell. C. fuel cell and an electric motor run by a rechargeable battery. D. gasoline engine and a cleaner diesel engine.

The hybrid car produced by Toyota, the Prius, is very popular and it uses a battery that Toyota claims should not have to be recharged or replaced during the lifetime of the car. The type of battery used in the Prius is A. alkaline. B. lead acid. C. nickel-cadmium. D. nickel-metal hydride.

Which is not true about Toyota's hybrid car, the Prius? A. It should never need to be connected to an external electrical outlet to charge its batteries. B. Despite its efficiency, it produces about the same amount of CO2 and a bit more NOx than Toyota's traditional vehicle. C. Upon braking, the vehicle is designed to transfer the kinetic energy of the car to a generator that charges the batteries. D. The gasoline engine and electric motor are used during normal driving and the batteries are used for a boost during quick acceleration.

What moves in the salt bridge from the cathode to the anode? A. electrons B. Zn+2 ions C. Cu+2 ions D. anions

Each statement is true. Which does not give an advantage to a hybrid car over a comparable all-battery-powered one? A. The hybrid car burns gasoline, thereby producing the pollutants that come from burning gasoline. B. The hybrid car is less dependent upon new technology and can take advantage of what is known about gasoline driven vehicles. C. As the hybrid car burns gasoline, some of the car's otherwise wasted energy is used to charge the batteries. D. Batteries used in vehicles are extremely heavy, so a hybrid car is lighter than a comparable all-battery-powered car and requires less energy overall to drive.

At present, it will be difficult and perhaps inappropriate to develop an economy based on burning hydrogen rather than natural gas or gasoline because A. hydrogen is a dirty fuel. Burning hydrogen produces significantly more pollutants than burning natural gas or gasoline. B. hydrogen is not an efficient fuel. Per gram, hydrogen has about the lowest heat of combustion of any known substance, much lower than natural gas or gasoline. C. although hydrogen is abundant, pure hydrogen is not found naturally on earth. Hydrogen is difficult or expensive to isolate and collect. D. being such a light element, hydrogen will not flow through pipelines the way natural gas or gasoline do. Hydrogen cannot easily be delivered from where it is produced to the places where it is needed.

What energy change is associated with the reaction to obtain one mole of H2 from one mole of water vapor? The balanced equation is 2 H2O(g) 2H2(g) + O2(g) and the relevant bond energies are: H H = 436 kJ/mol; H O = 467 kJ/mol; O O = 146 kJ/mol; O O = 498 kJ/mol. A. -249 kJ B. +249 kJ C. -436 kJ D. +436 kJ

Which means for obtaining hydrogen from water would require the most energy? A. React water at high temperatures (steam) with certain common substances such as natural gas or coke (a solid that almost pure carbon). B. Use the excess heat energy from nuclear fission to supply the energy needed to decompose water into hydrogen and oxygen. C. Burn fuels to heat water to the temperature at which it decomposes into hydrogen and oxygen. D. Electrolyze water (run an electric current through it) to decompose it into hydrogen and oxygen.

For safety and other practical reasons, the most logical use for hydrogen as a fuel in the near future is A. in an electric power plant. B. in a fuel cell. C. for running an automobile. D. for nuclear fusion.

Which has not been suggested as a reasonably practical way to store large amounts of hydrogen in relatively small spaces for its use as a fuel? A. Liquefy hydrogen under pressure and store it much as we do with liquefied natural gas today. B. Absorb hydrogen onto activated charcoal; then heat the mixture to release the hydrogen. C. Store it in the form of ionic metal hydrides, such as LiH, which release hydrogen gas when they react with water. D. Encapsulate hydrogen molecules in fullerene molecules (large, carbon-based molecules that can act like cages) that may be heated later to release the hydrogen.

The sun's energy that reaches Earth's surface each hour of every day is enough to meet the world's total energy demand for one A. day. B. week. C. month. D. year.

Sunlight (solar radiation) may be turned directly into electricity using ______ cells. A. fuel B. photovoltaic C. electrolytic D. lead-acid

To date, solar radiation is not a practical source for the production of electricity used to power A. electric highway signs. B. security lighting in parking lots. C. satellites in orbit around the earth. D. fleets of taxis.

To date, solar radiation is not a practical source for the production of electricity used to power A. electric highway signs. B. security lighting in parking lots. C. satellites in orbit around the earth. D. fleets of taxis.

Semiconductors, such as the element silicon, may be used in cells that convert solar radiation to electricity. One of the major difficulties encountered in using silicon is that it A. is one of the rarest of all elements and therefore difficult to find on earth. B. is expensive to produce large quantities of extremely pure silicon. C. quickly evaporates when isolated in a pure state. D. is the most active of all the elements, so it cannot be prepared in a pure state.

The "doping" of a semiconductor to improve its performance means A. slightly raising the temperature of a pure semiconductor to improve the ability of its electrons to flow from atom to atom. B. fusing layers of two different pure semiconductors together to give the electrons that absorb the solar radiation characteristics of the electrons of both semiconductors. C. mixing large amounts of a metal with small amounts of a semiconductor so that the metal itself becomes a semiconductor. D. adding small amounts of other elements to the pure semiconductor to change the freedom of electron motion throughout the crystal.

In a solar cell, placing semiconductors of the p-type and n-type in contact with each other via a conducting wire accomplishes these two things: A. It ensures that the current flows in a specific direction as it facilitates the conduction of electricity. B. It ensures that only certain energies of solar radiation cause electricity to flow as it facilitates the conduction of electricity. C. It ensures that only certain energies of solar radiation cause electricity to flow as it facilitates the flow of electricity in either direction. D. It ensures that only oxidation takes place as it facilitates the conduction of electricity

The efficiency of using most commercial semiconductors to convert solar radiation into electricity is approximately ______ percent. A. 2 B. 15 C. 35 D. 75

Silicon has 4 electrons in its outer energy level, gallium has 3. Adding small amounts of gallium to pure silicon A. destroys the ability of the silicon to act as a semiconductor. B. provides the basis for using the silicon as a fuel cell. C. creates a p-type semiconductor. D. creates an n-type semiconductor.

Which increases the efficiency of a photovoltaic or solar cell? I. Replacing crystalline silicon with its non-crystalline form. II. Increasing the number of alternating p- and n-type layers of semiconductors. III. Decreasing the thickness of each alternating p- and n-type layer of semiconductor. A. I and II only B. II and III only C. I and III only D. I, II, and III

Approximately how many homeowners worldwide use solar cells to generate their own electricity? A. 50,000 B. 500,000 C. 5,000,000 D. 10,000,000

Which argument(s) for the increasing use of solar energy is/are valid? I. Solar cells are becoming cheaper and increasingly more efficient. II. The cost of generating electricity from fossil fuels is increasing. III. Limited and uncertain supply and the increasing requirements for pollution control are raising the cost of using fossil fuels. A. I only B. II only C. I and III only D. II and III only

Among the alternative sources for generating electricity are I. batteries. II. fuel cells. III. solar cells. In populated but remote regions where it has proven too expensive or too difficult to establish electrical networks, which is/are the most viable alternative method(s) of providing electricity? A. I only B. I and II only C. II and III only D. I and III only

Batteries must be used in addition to solar cells when generating household electricity because A. solar cells can generate electricity only via the output of a battery. B. solar cells can generate only a small fraction of the total energy needed by a household at any one time. C. solar cells generate so much electricity that they will overheat if they cannot transfer the excess electricity somewhere to dissipate the extra heat. D. batteries must supply the energy when sunlight is not available.

Which is not a valid argument supporting the switch from using fossil fuels to using solar cells to generate our electricity? A. The conversion reduces environmental damage from the extraction and transport of fossil fuels. B. The conversion will lower the level of air pollution from sulfur and nitrogen oxides. C. The conversion can be done quickly, efficiently, and relatively inexpensively if we just put our minds and our will to it. D. The conversion will reduce the potential for global warming as less carbon dioxide is produced in the generation of electricity.

Which is not a valid argument supporting the continued use of fossil fuels? A. We will still be using only a small fraction of the total usable surface of the earth if we open new, formerly protected areas to exploration. B. We are continuing to find more efficient ways to use fossil fuels as energy resources. C. We will recover more from a particular source than we were able to in the past as we improve the technologies by which we recover these fuels from the earth. D. We are improving the technologies used to remove pollutants from our fossil fuels before we use them and from the materials produced after we use them.

In this photovoltaic (solar) cell, the n-type semiconductor is in the region labeled A. A B. B C. C D. D

In the lead-acid (storage) battery, the cathode is the A. H2SO4 electrolyte. B. negative plates, lead/spongy lead. C. positive plates, lead/PbO2. D. casing enclosing the entire battery

In recently designed fuel cells the corrosive acidic or alkaline electrolyte is replaced with A. a solid polymer. B. mercury. C. lead. D. pure water.

A candle may be considered a more efficient producer of light than a flashlight because it A. converts chemical energy directly into light. B. produces more heat than a flashlight. C. does not have a battery to recharge or replace. D. may be used in remote locations far from electrical networks or power lines.

The aluminum-air battery is being considered for use in automobiles. In this battery, aluminum metal undergoes oxidation to Al3+ ions and forms Al(OH)3. O2 from the air undergoes reduction to OH¯ ions. Which half-reaction occurs at the anode? A. formation of OH¯ ions from O2. B. capturing O2 from the air so that it may form the OH¯ ions. C. formation of Al3+ ions from aluminum. D. reaction of Al3+ ions with hydroxide ions to produce Al(OH)3.

A NiCd battery uses nickel and cadmium to produce a potential difference. Using these equations, answer the following questions. I. 2NiO(OH) (s) + 2H2O (l) + 2 e- 2Ni(OH)2 (s) + 2 OH¯ (aq) II. Cd (s) + 2OH¯ (aq) Cd(OH)2 (s) + 2e¯ III. Cd (s) + 2NiO(OH) (s) + 2 H2O (l) 2 Ni(OH)2 (s) + Cd(OH)2 (s)

Which equation represents what takes place at the anode? A. I B. II C. III D. I and II

Which equation represents the whole chemical reaction within the galvanic cell? A. I B. II C. III D. I and II

Which equation best represents the reduction half-reaction? A. I B. II C. III D. I and II

Of the different fuel cells discussed, which is currently the best option for powering automobiles? A. PEM B. phosphoric acid C. DMFC D. SOFC

Electrolysis is a process that A. produces an electrical current. B. requires an electrical current. C. produces heat energy. D. requires heat energy.

What is the primary reason that the United States is not rapidly becoming a hybrid nation? A. Gasoline is still reasonably priced. B. Hybrid cars release more CO2 than regular cars. C. Hybrid cars are relatively expensive. D. Hybrid cars get better gas mileage.

Metallic bonds are formed by the A. equal sharing of electrons between two atoms. B. unequal sharing of electrons between two atoms. C. formation of a "sea of electrons" shared by many atoms. D. transfer of electrons between two atoms.

Which of the following statements is not true about PEM fuel cells? A. PEM fuel cells rely on inexpensive catalysts. B. PEM fuels cells are cleaner than gasoline powered vehicles. C. PEM fuel cells have safe and efficient fuel storage. D. PEM fuel cells have limited driving range.

Which statement associated with the all-battery driven EV-1 vehicles is not true? A. Batteries lose power at low temperatures. B. Recharging batteries is a clean process. C. Electrical power generation is inefficient. D. EV-1 vehicles have zero emissions on the road

Why is it so expensive to ship hydrogen as a liquid as is often done with other gas? A. Hydrogen is very heavy to ship. B. Hydrogen is very dense to ship. C. Hydrogen has to be shipped at a very low temperature. D. Hydrogen in very flammable.

All of the following are true of energy released from a process except: A. it carries a negative sign. B. it could be described as evolved energy. C. it means more energy is produced than required. D. it would feel cold.

Reforming processes can store hydrogen fuel in a liquid form as another molecule. Which of the following cannot be reformed into hydrogen? A. methanol B. gasoline C. diesel D. carbon dioxide

Direct methanol fuel cells (DMFC) have several advantages over fuel reformers. Which is not an advantage of DMFC? A. increased portability B. decreased size C. cheaper metal catalysts D. CO2 production

Which of the following is not an advantage of solid oxide fuel cells (SOFC's) over direct methanol fuel cells (DMFC's)? A. SOFC's are quick starters. B. SOFC's can operate at higher temperatures. C. SOFC's can tolerate greater impurities. D. SOFC's can be used to turn turbines.

Why doesn't water naturally become hydrogen and oxygen gas when exposed to light? A. There isn't enough energy in the light. B. Thermal energy is the only appropriate type of energy to split water. C. You must use electrons to split water. D. Water doesn't absorb the proper wavelength of light to split.

What metal is used to dope an n-type semiconductor? A. arsenic B. cadmium C. gallium D. silicon

Given this diagram, this semiconductor is A. made of pure silicon. B. carrying an extra electron. C. missing an electron. D. excited by a photon.

How do the interactions that are broken in water when it is boiled compare with those broken when water is electrolyzed? A. Boiling water breaks intermolecular attractions and electrolysis breaks covalent bonds. B. Boiling water breaks covalent bonds and electrolysis breaks intermolecular attractions. C. Boiling water and electrolysis of water break covalent bonds. D. Boiling water and electrolysis of water break intermolecular forces.

What about the bonding of silicon makes it useful as a semiconductor but not as a conductor of electricity? A. The electrons are transferred forming ions that conduct electricity. B. The electrons are shared in covalent bonds between atoms. C. The electrons form a "sea of electrons" that move between many atoms. D. The electrons are somewhat shared and somewhat transferred because it is a metalloid.