Deck 21: Nuclear Chemistry-The Risks and Benefits

Question 1

What other particle is formed during the fusion of two protons to form deuterium?

A)"proton"
B)"neutron"
C)"electron"
D)"positron"
E)" $\gamma$ ray"

Answer 1

"positron"

Question 2

Nuclear fusion produces energy because ________

A)neutrons are produced.
B)the total mass of the products is less than that of the reactants.
C)the total mass of the products is more than that of the reactants.
D)it is a very powerful chemical reaction.
E)photons are produced.

Answer 2

the total mass of the products is less than that of the reactants.

Question 3

What is the correct symbol for a positron?

A)
B)
C)
D)
E)

Answer 3

Question 4

Why are higher temperatures necessary for fusion of helium nuclei than for hydrogen nuclei?

A)Helium is chemically inert.
B)Helium nuclei are heavier than hydrogen nuclei.
C)The boiling point of helium is higher than that of hydrogen.
D)Because E = mc² and helium nuclei are heavier than hydrogen nuclei.
E)The positive charges on helium nuclei are greater than those on the hydrogen nuclei.

Question 5

What is the correct symbol for a $\beta$ particle?

A)
B)
C)
D)
E)

Question 6

Hydrogen fusion always produces ________

A)"an increase of mass number."
B)" $\beta$ particles."
C)"a new element."
D)"a change in the atomic number."
E)"positrons."

Question 7

Which of the following statements regarding Einstein's equation relating mass and energy is correct?

A)Ordinary chemical change occurs too slowly for the conversion of mass to energy to be observed.
B)The amount of energy available from a nuclear reaction decreases as the change in mass increases.
C)Small changes in mass result in very large changes in energy because of the speed of light squared dependence.
D)The mass of the universe must remain constant even though energy is released during nuclear change.
E)The energy of the universe is decreasing because the mass of the universe is increasing.

Question 8

What particle is formed during the fusion of a proton and a neutron?

A)
B)
C)
D)
E)

Question 9

________ are elementary particles that act as carriers for the force between quarks.

A)Muons
B)Mesons
C)Leptons
D)Higgs bosons
E)Gluons

Question 10

Which of the following reactions is NOT correct?

A)
B)
C)
D)
E)

Question 11

High-energy radiation produced during nuclear change consists of ________

A)"cosmic rays."
B)" $\gamma$ rays."
C)"gluons."
D)"electrons."
E)"positrons."

Question 12

What repulsive forces must be overcome for any element other than hydrogen to exist?

A)The repulsion between neutrons and other neutrons.
B)The repulsion between protons and other protons.
C)The repulsion between protons and neutrons.
D)The repulsion between positrons and electrons.
E)The repulsion between neutrons and electrons.

Question 13

Which statement is NOT correct? During primordial nucleosynthesis,________

A)neutrons and protons fused together to form deuterons.
B)deuterons fused together to form alpha particles.
C)more stable nuclides were formed from less stable nuclides.
D)gamma rays were produced.
E)colliding pairs of electrons annihilated each other.

Question 14

As the charges of identical small nuclei increase,the energy required to initiate nuclear fusion of them ________

A)decreases.
B)increases.
C)stays the same.
D)is proportional to their mass.
E)is inversely proportional to their mass.

Question 15

The nucleus is held together by ________

A)the strong nuclear force.
B)the electromagnetic force.
C)the electroweak force.
D)Higgs bosons.
E)quarks.

Question 16

When a positron and an electron collide,they ________

A)form a neutron.
B)strongly repel one another and recoil.
C)annihilate each other and produce $\gamma$ rays.
D)form a proton.
E)form a neutron and emit $\gamma$ rays.

Question 17

Which of the following statements regarding ordinary chemical reactions and nuclear reactions is correct?

A)The identity of an atom may change during a nuclear reaction.
B)The identity of an atom may change during an ordinary chemical reaction.
C)There can never be a change in the total mass measured before and after a chemical reaction or a nuclear reaction.
D)The energy change associated with a chemical reaction is always much greater than that of a nuclear reaction.
E)The free energy of the universe always increases during nuclear reactions.

Question 18

Extremely high temperatures are required to initiate nuclear fusion,but then energy is released by nuclear fusion.This is analogous to ________

A)boiling a liquid by heating it.
B)melting a solid by heating it.
C)lighting a match to start a fire.
D)two magnets attracting each other.
E)climbing up a hill and then skiing down.

Question 19

Which of the following is thought to give particles of matter their observed masses?

A)muons
B)mesons
C)leptons
D)Higgs bosons
E)gluons

Question 20

Which statement is NOT correct? In hydrogen fusion in our sun,________

A)a neutron and a proton fuse together to form a deuteron.
B)two protons fuse together to form a deuteron and a positron.
C)a deuteron and a proton fuse to produce a helium-3 nuclide.
D)two helium-3 nuclides fuse to produce a helium-4 nuclide and two protons.
E)more stable nuclides are produced from less stable nuclides.

Question 21

The most naturally abundant nuclides are those that ________

A)have an odd number of protons and an odd number of neutrons.
B)have an even number of protons and an even number of neutrons.
C)have noble gas configurations of electrons.
D)can be produced by fission reactions.
E)can be produced by fusion reactions.

Question 22

A barrel of oil produces about 5.9 10⁶ kJ of energy.Fission of 235 g of uranium-235 releases 2.1 10¹⁰ kJ of energy.How many barrels of oil are equivalent to 1.0 kg of uranium-235?

A)3600
B)15,000
C)840,000
D)110,000
E)55,000

Question 23

When carbon burns to produce carbon dioxide,395 kJ/mol of energy is released.Approximately how much greater is the energy released per mole of deuterium in the following fusion process: 2 ²H $\to$ ⁴He? The atomic masses are 2.0141 g/mol for ²H and 4.0026 g/mol for ⁴He.(1 kJ = 1000 kg m²/s²)

A)10²
B)10⁴
C)10⁶
D)10⁸
E)10¹⁰

Question 24

The isotope "belt of stability" is an area in a plot of ________

A)nuclear binding energy vs.atomic number.
B)isotopic strength vs.isotopic weakness.
C)nuclear mass vs.mass number.
D)neutron number vs.atomic number.
E)mass number vs.atomic number.

Question 25

What quantity of energy would be produced as one atom of plutonium-238 undergoes $\alpha$ decay? Round your answer to two significant figures.

A)"6.0 10^-7 J"
B)"2.6 10^-8 J"
C)"7.0 10^-10 J"
D)"1.1 10^-12 J"
E)"4.9 10^-12 J"

Question 26

The peak in nuclear binding energy/nucleon occurs for an isotope of ________

A)helium.
B)carbon.
C)uranium.
D)iron.
E)lead.

Question 27

Compare the energy released by the collisions and annihilation of (1)an electron and a positron and (2)a proton and an antiproton.

A)The energy released would be the same.
B)The energy released in (2)would be much greater than that released in (1).
C)The energy released in (1)would be much greater than that released in (2).
D)Energy is consumed in these processes,not released.
E)Energy is not released in these collisions.

Question 28

Suppose the reaction produces 1.664 10¹⁰ kJ/mol of energy.Calculate the change in mass in grams that occurs when one mole of U-235 reacts with one mole of neutrons.E = mc²,where c = 2.998 10⁸ m/s; 1 kg = 6.0221415 10²⁶ amu; 1 J = 1kg . m²/s².

A)0.185 g
B)0.555 g
C)0.898 g
D)5.41 g
E)9.22 10^-17 g

Question 29

When bombarded by a proton,a lithium-7 nucleus reacts to form two $\alpha$ particles.How many kilojoules per gram of Li-7 are released during this nuclear transformation? (1 kJ = 1000 kg m²/s²)

A)1.7 10⁹ kJ/g
B)3.9 10⁴ kJ/g
C)5.6 10^-9 kJ/g
D)7.9 10⁵ kJ/g
E)2.4 10⁸ kJ/g

Question 30

What quantity of energy would be produced when one mole of deuterium reacts with one mole of tritium to form helium and a neutron? (1 kJ = 1000 kg m²/s²)

A)1.7 10¹² J
B)5.6 10⁶ J
C)2.8 10^-9 J
D)9.2 10¹³ J
E)3.1 10⁸ J

Question 31

Which of the following statements regarding the use of fusion reactions to meet Earth's energy needs is NOT correct?

A)The products of fusion reactions are not hazardous as are those of fission reactions.
B)The plasmas of high-energy particles in which fusion reactions occur can be contained by magnetic fields.
C)The amount of energy available from fusion reactions is much larger than any that generated by other process.
D)The use of lithium in "breeder" blankets is a disadvantage of the technology in development.
E)The limited supply of deuterium is a disadvantage of the technology in development.

Question 32

What quantity of energy would be produced as 1.00 g of plutonium-238 undergoes $\alpha$ decay? Round your answer to two significant figures.

A)1.2 10¹⁰ J
B)2.7 10⁹
C)3.5 10⁸J
D)4.4 10¹⁰ J
E)6.2 10^-13 J

Question 33

When 4 protons and 4 neutrons combine to form a beryllium-8 nucleus,energy is released.Calculate the nuclear binding energy per nucleon.Here are some helpful data: ⁸Be isotopic mass

A)1.20 10^-6 J/nucleon
B)1.08 10^-9 J/nucleon
C)1.13 10^-12 J/nucleon
D)8.73 10^-12 J/nucleon
E)1.08 10^-15 J/nucleon

Question 34

The mass of a particular isotope is given by ________

A)the mass number.
B)adding the masses of protons,neutrons,and electrons.
C)dividing the mass number by 6.02 10²³.
D)measuring it.
E)dividing the molar mass of the element by 6.02 10²³.

Question 35

All elements with Z > 83 are ________

A)synthetic.
B)produced by nuclear fission.
C)radioactive.
D)not found in nature.
E)unreactive.

Question 36

What quantity of energy would be produced as 1.00 kg of plutonium-238 undergoes $\alpha$ decay? Round your answer to two significant figures.

A)4.4 10¹³ J
B)3.5 10¹¹ J
C)6.2 10^-10 J
D)1.2 10¹³ J
E)2.7 10¹² J

Question 37

Which one of the following statements is NOT correct?

A)Nucleons are held together in a nuclide by the electromagnetic force.
B)Oxygen-15 is unstable because it has too few neutrons.
C)All nuclides with Z > 83 decay into more stable nuclides with smaller Z values.
D)As the atomic number increases,the ratio of neutrons to protons in a nuclide increases.
E)Generally the number of neutrons in a nuclide equals the number of protons,or nearly so,when the atomic number is small,i.e.,Z < 18.

Question 38

What quantity of energy would be produced when one gram of deuterium and one gram of tritium are allowed to completely react to form helium and a neutron? (1 kJ = 1000 kg m²/s²)

A)5.6 10¹¹ J
B)1.7 10¹² J
C)2.8 10^-9 J
D)9.2 10¹³ J
E)3.1 10⁸ J

Question 39

The heaviest elements will generally have a neutron-to-proton ratio about equal to ________

A)0.5.
B)0.8.
C)1.0.
D)1.3.
E)1.5.

Question 40

Light elements with Z < 20 generally have neutron-to-proton ratios about equal to ________

A)0.5.
B)0.8.
C)1.0.
D)1.3.
E)1.5.

Question 41

For which of the following isotopes would it be unlikely to observe $\beta$ ^-decay?

A)"²⁰F"
B)"¹³¹I"
C)"²⁷Mg"
D)"¹⁹O"
E)"¹³N"

Question 42

Strontium-88 is the most abundant stable isotope of strontium.Strontium-90 is a particularly hazardous radioactive isotope because,as an alkali earth metal,it will substitute for calcium in bones and teeth.Predict its decay pathway.

A)" $\alpha$ emission"
B)" $\beta$ ^- emission"
C)"positron emission"
D)" $\gamma$ emission"
E)"X-ray emission"

Question 43

Which one of the following statements is NOT correct?

A)Carbon-10 is unstable because it has too few neutrons.
B)All nuclides with Z > 83 decay into nuclides with smaller Z values.
C)Generally,the number of neutrons in a nuclide is equal to or less than the atomic number.
D)As the atomic number increases,the ratio of neutrons to protons in a nuclide increases.
E)It is very unusual to find a nuclide with an odd number of protons and an odd number of neutrons.

Question 44

Radon-220 decays to polonium-216.What particle is emitted?

A)" $\beta$
B)"positron"
C)"neutron"
D)" $\alpha$ "
E)" $\gamma$ "

Question 45

Francium-226 is a $\beta$ ^-emitter.What is the product of the radioactive decay of Fr-226?

A)astatine-222
B)radon-226
C)radium-226
D)actinium-230
E)francium-225

Question 46

Sodium-22 undergoes electron capture.Identify the resulting isotope.

A)magnesium-22
B)sodium-23
C)neon-21
D)magnesium-21
E)neon-22

Question 47

Nitrogen-13 decays by positron emission to produce ________

A)carbon-13.
B)oxygen-17.
C)boron-11.
D)carbon-14.
E)boron-13.

Question 48

Which of the following nuclides are most likely to be unstable because they have neutron-to-proton ratios greater than that predicted by the belt of stability?
(I)carbon-14
(II)sodium-26
(III)sulfur-26
(IV)aluminum-27
(V)phosphorus-31

A)only I
B)I and II
C)II and III
D)III,IV,and V
E)all of these

Question 49

Positron emission is associated with ________

A)conversion of a neutron to a proton.
B)conversion of a proton to a neutron.
C)increase in mass number.
D)decrease in mass number.
E)emission of alpha particles.

Question 50

For which of the following isotopes would it be unlikely to observe $\beta$ ⁺ decay?

A)"¹²⁰Te"
B)"⁹⁶Ru"
C)"¹⁰⁶Cd"
D)"¹¹⁸Sn"
E)"¹²⁴Xe"

Question 51

Beta emission is associated with ________

A)conversion of a neutron to a proton.
B)conversion of a proton to a neutron.
C)increase in mass number.
D)decrease in mass number.
E)emission of alpha particles.

Question 52

The first step in the disintegration of uranium-238 produces thorium-234.What particle is emitted in this reaction?

A)" $\alpha$ particle"
B)"neutron"
C)"proton"
D)" $\beta$ ^-particle"
E)" $\gamma$ ray"

Question 53

The heaviest stable nucleus is an isotope of ________

A)platinum.
B)gold.
C)lead.
D)bismuth.
E)xenon.

Question 54

For which of the following isotopes would it be unlikely to observe electron capture?

A)"²⁸Al"
B)"⁷Be"
C)"⁴⁹V"
D)"⁷³As"
E)"¹²⁵I"

Question 55

Cobalt-60 decays to nickel-60.What particle is emitted?

A)"proton"
B)"neutron"
C)" $\beta$ "
D)"positron"
E)" $\alpha$ "

Question 56

Plutonium-238 is an $\alpha$ emitter.What is the product of the radioactive decay of Pu-238?

A)thorium-230
B)uranium-234
C)curium-242
D)californium-246
E)plutonium-234

Question 57

In 1913,an element was known to "emanate" from radium-226 by $\alpha$ emission and then to decay to polonium-218,also by $\alpha$ emission.What was the unknown element?

A)radon-222
B)lead-214
C)plutonium-238
D)bismuth-214
E)lead-218

Question 58

Cobalt-56 decays by emitting a positron.What is the product?

A)cobalt-55
B)cobalt-56
C)nickel-56
D)iron-56
E)iron-55

Question 59

Electron-capture is associated with ________

A)conversion of a neutron to a proton.
B)conversion of a proton to a neutron.
C)increase in mass number.
D)decrease in mass number.
E)emission of alpha particles.

Question 60

Cobalt-60 is a radioactive isotope of Co that is used for radiation therapy.It is originally produced from iron-58,which is first converted to Fe-59.Which particle did the Fe-58 absorb to become Fe-59?

A)" $\alpha$ particle"
B)"neutron"
C)"proton"
D)"electron"
E)" $\gamma$ ray"

Question 61

Which of the following statements regarding nuclear decay is NOT correct?

A)Radioactive decay is a random process.
B)All nuclei of a radionuclide decay at the same rate.
C)Nuclear decay always follows first-order kinetics.
D)A large number of nuclei is generally required to determine the half-life of a radionuclide.
E)In general,the more unstable the radionuclide,the shorter the half-life.

Question 62

Which graph below describes the decay of two radioactive nuclides,P and Q,when the half-life of Q is longer than the half-life of P? In these graphs ln[N_t/N₀] is plotted on the y-axis with time (t)on the x-axis.N₀ = number of radioactive nuclides present at time = 0 and N_t = number present at time = t.

A)

B)

C)

D)

E)

Question 63

Suppose 89.4% of a sample of radioactive sodium-24 has decayed after two days.Estimate the half-life of Na-24.

A)3.89 days
B)3.24 days
C)14.8 hours
D)12.3 hours
E)1.79 days

Question 64

Which isotope is produced when ²¹⁶Po decays by emitting an $\alpha$ particle followed by two $\beta$ ^- particles?

A)"²¹⁰Po"
B)"²¹²Po"
C)"²¹⁴Po"
D)"²¹⁸Po"
E)"²²⁰Po"

Question 65

Calfornium-249 decays to thallium-205 through a series of nuclear reactions.Only $\alpha$ particles and $\beta$ ^- particles are emitted.How many $\beta$ ^- particles are emitted?

A)11
B)9
C)7
D)3
E)5

Question 66

Rhenium-185 is a stable isotope.Rhenium-188 is a radioisotope for treatment of cancer.What type of emission is likely for this isotope?

A)" $\alpha$ "
B)" $\beta$ ^-"
C)"positron"
D)" $\gamma$ ray"
E)"X-ray"

Question 67

Suppose 38.0% of a sample of radioactive polonium-218 remains after 4.33 minutes.Estimate the half-life of Po-218.

A)3.30 minutes
B)1.19 minutes
C)6.20 minutes
D)1.40 minutes
E)3.10 minutes

Question 68

The half-life of chromium-51 is 27.8 days.How many half-lives have elapsed after one year?

A)2.32 t
B)32.4 t
C)1.08 t
D)13.1 t
E)0.0762 t

Question 69

Cobalt-59 is a stable isotope.Cobalt-60 is used as a radioactive source approved by the FDA for irradiation of food.This process kills microbes and insects and can delay ripening.What decay pathway is likely for cobalt-60?

A)"X-ray emission"
B)" $\gamma$ emission"
C)"positron emission"
D)" $\beta$ ^- emission"
E)" $\alpha$ emission"

Question 70

How many $\alpha$ and how many $\beta$ ^- particles are emitted when thorium-232 decays to form lead-208?

A)6 $\alpha$ ,no $\beta$ ^-
B)6 $\alpha$ ,4 $\beta$ ^-
C)12 $\alpha$ ,8 $\beta$ ^-
D)12 $\alpha$ ,4 $\beta$ ^-
E)8 $\alpha$ ,6 $\beta$ ^-

Question 71

Tritium (³H)is used in glowing "EXIT" signs conveniently located where there is no electricity for lightbulbs.What decay route is likely for tritium?

A)" $\beta$ ^- emission"
B)" $\beta$ ^-emission"
C)" $\alpha$ emission"
D)" $\gamma$ emission"
E)"X-ray emission"

Question 72

Fluorine-18,which is often used in PET scans to locate tumors,decays to form a positron and oxygen-18.After 90.0 minutes,1.00 ¹⁸O is present relative to every 1.30 ¹⁸F.Estimate the half-life of F-18.

A)288 minutes
B)109 minutes
C)156 minutes
D)175 minutes
E)238 minutes

Question 73

Predict the daughter nuclide formed when phosphorus-32 undergoes radioactive decay.

A)phosphorus-31
B)silicon-32
C)aluminum-28
D)sulfur-32
E)sodium-24

Question 74

Which graph below describes the decay of two radioactive nuclides,P and Q,when the half-life of Q is shorter than the half-life of P? In these graphs ln[N_t/N₀] is plotted on the y-axis with time (t)on the x-axis.N₀ = number of radioactive nuclides present at time = 0 and N_t = number present at time = t.

A)

B)

C)

D)

E)

Question 75

After uranium-238 undergoes a series of eight $\alpha$ decays and six $\beta$ ^- decays,what daughter nuclide results?

A)polonium-216
B)radon-222
C)ytterbium-182
D)osmium-182
E)lead-206

Question 76

In the initial sequence of thorium-232 decay,an $\alpha$ particle is emitted,followed by a $\beta$ ^- particle.What is the product of these two decay steps?

A)radium-228
B)actinium-228
C)thorium-228
D)francium-228
E)The correct answer differs from these possibilities.

Question 77

A half-life is ________

A)the life that a nuclear chemist leads.
B)half of the lifetime of an unstable nucleus.
C)the time for one-half of the unstable nuclei to decay.
D)constantly changing.
E)independent of the rate constant for decay.

Question 78

Calfornium-249 decays to thallium-205 through a series of nuclear reactions.Only $\alpha$ particles and $\beta$ ^- particles are emitted.How many $\alpha$ particles are emitted?

A)22
B)18
C)15
D)11
E)9

Question 79

Iodine-131 has a half-life of 8.1 days and is used as a tracer for the thyroid gland.If a patient drinks a sodium iodide (NaI)solution containing iodine-131,how many days will it take for the concentration of iodine-131 to drop to 5.0% of its initial concentration?

A)19 days
B)0.81 day
C)8.1 days
D)35 days
E)4.3 days

Question 80

Strontium-90 is most likely to decay by ________

A)" $\gamma$ emission."
B)"electron capture."
C)"positron emission."
D)" $\alpha$ emission."
E)" $\beta$ ^- emission."