Nuclear Chemistry And Radiochemistry | Full Test Bank Ch.21

CHAPTER 21

NUCLEAR CHEMISTRY AND RADIOCHEMISTRY

CHAPTER STUDY OBJECTIVES

1. Explain the forces that hold nuclei together.

SKILLS TO MASTER: Writing nuclide symbols; calculating binding energies; predicting stabilities of nuclides

KEY CONCEPTS: The mass number is the sum of the atomic number and the number of neutrons. Energy and mass are interconvertible. Most stable nuclides have even numbers of protons and neutrons.

2. Describe nuclear decay processes and calculate rates of decay.

SKILLS TO MASTER: Balancing nuclear reactions; calculating the decay rate of a nuclide; calculating the half-life of a nuclide

KEY CONCEPTS: Mass number and electrical charge are conserved during a nuclear reaction. All nuclear decay processes obey first-order kinetics.

3. Describe how products are synthesized in induced nuclear reactions.

SKILLS TO MASTER: Balancing neutron-capture reactions; balancing binuclear reactions

KEY CONCEPTS: In an induced nuclear reaction, a nuclear projectile collides and reacts with another nucleus.

4. Describe the fission process and the essential features of a fission reactor.

SKILLS TO MASTER: Calculating the energy released by a fission reaction

KEY CONCEPTS: Neutron capture by a fissionable nucleus produces a highly unstable nucleus that distorts and then splits into smaller nuclei and a few free neutrons. Fission gives a wide range of product nuclides from A = 77 to A = 157. The critical mass is the amount of material that is just large enough to recapture one neutron, on average, for every fission reaction.

5. Describe the fusion process and the essential features of a fusion reactor.

SKILLS TO MASTER: Explaining the origins of heavy nuclides in the universe

KEY CONCEPTS: Initiating a fusion reaction requires enormous inputs of energy to overcome electrical repulsion of protons in the nuclei.

6. Explain the effects of ionizing radiation.

SKILLS TO MASTER: Knowing the health effects of radiation doses

KEY CONCEPTS: Radiation damage is caused by the ionizing effects of high-energy particles. Different types of radiation penetrate matter to different depths and produce different damage.

7. Explain some practical applications of radioactivity.

SKILLS TO MASTER: Calculating the age of an object using radioactive dating

KEY CONCEPTS: The precisely known half-lives of many nuclides can be used to estimate the age of an object. Radioactive nuclides can be used as tracers in biological and environmental studies.

Multiple Choice QUESTIONS

1. The nuclide with the formula is best described as

a) stable.

b) containing 81 neutrons and having a mass number of 205.

c) containing 205 protons and 81 neutrons.

d) containing 81 neutrons and 124 protons.

e) containing 124 neutrons and 81 protons.

Difficulty: Easy

Learning Objective: Explain the forces that hold nuclei together.

Section Reference: 21.1 Nuclear Stability

2. Seborgium’s most stable isotope contains one-hundred-six protons and one-hundred-fifty-seven neutrons. This nuclide’s symbol is

a) .S

b) .

c) .

d) .

e) .

Difficulty: Easy

Learning Objective: Explain the forces that hold nuclei together.

Section Reference: 21.1 Nuclear Stability

3. The nuclide with the formula is best described as

a) containing 136 neutrons and 87 protons.

b) containing 87 neutrons and having a mass number of 223.

c) containing 223 electrons and 87 protons.

d) containing 87 neutrons and 136 protons.

e) stable.

Difficulty: Easy

Learning Objective: Explain the forces that hold nuclei together.

Section Reference: 21.1 Nuclear Stability

4. Which force is responsible for repulsions in the nucleus?

a) gravitational force

b) electrical force

c) magnetic force

d) strong nuclear force

e) the star wars force

Difficulty: Easy

Learning Objective: Explain the forces that hold nuclei together.

Section Reference: 21.1 Nuclear Stability

5. Calculate the binding energy per mole of nucleons for the boron isotope with mass of 12.0143 amu.

(If needed, use the following equations: E = mc² c = 3.0 x 10⁸m/s E = Δm(8.988 x10¹⁰ kJ/g)

mass_proton = 1.007276 g/mol mass_neutron = 1.008665 g/mol mass_electron = 0.0005486)

a) –1.537x10⁹ kJ/mol

b) –6.404x10⁸ kJ/mol

c) 6.404x10⁸ kJ/mol

d) 1.736x10¹⁰ kJ/mol

e) –7.685x10⁸ kJ/mol

Difficulty: Medium

Learning Objective: Explain the forces that hold nuclei together.

Section Reference: 21.1 Nuclear Stability

Feedback: a) energy per proton; b) correct answer; c) incorrect sign; d) based on only 5 neutrons; e) based on 10 nucleons

6. Nuclei that lie above the belt of stability generally decay by

aemission.

b)emission.

c) electron capture.

d) positron emission.

e emission.

Difficulty: Medium

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

7. Nuclei that lie below the belt of stability generally decay by

a emission.

b emission.

c) electron capture.

d) x-ray emission.

e emission.

Difficulty: Medium

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

8. Nuclei that lie below the belt of stability are characterized by

a) high numbers of neutrons.

b) low neutron to proton ratio.

c) high neutron to proton ratio.

d particle emission.

e) green colours.

Difficulty: Easy

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

9. Strontium-90 decays by emission. Which of the following is the decay product?

a)

b)

c)

d)

e)

Difficulty: Medium

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

10. ²³⁸U is an unstable nuclide that undergoes multiple decay events. One sequence is
––––The product nuclide is

a) ²²⁰Rn.

b) ²²²Rd.

c) ²¹⁸Po.

d) ²²²Rn.

e) ²²⁰Rd.

Difficulty: Medium

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

11. ²²²Rn is an unstable nucleus that is hazardous. Several pathways are known for its decomposition. One is ––-–– The product nuclide is

a) ²¹⁰Tl.

b) ²¹⁰Pb.

c) ²¹⁰Po.

d) ²¹⁴Po.

e) ²⁰⁶Tl.

Difficulty: Medium

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

12. Which unstable species decays with the emission of an alpha and a gamma particle to form ²²²Rn?

(If needed, use the following equation: )

a) ²²⁶Po

b) ²²⁶Fr

c) ²²⁶Ra

d) ²²⁴Ra

e) ²²⁴Po

Difficulty: Medium

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

Feedback: a) correct mass number, incorrect atomic number; b) correct mass number, incorrect atomic number; c) correct answer; d) correct atomic number incorrect mass number; e) incorrect mass and atomic numbers

13. ⁶⁴Ni and a positron are formed when which unstable species decays?

(If needed, use the following equation: )

a) ⁶⁴Co

b) ⁶⁴Cu

c) ⁶⁵Co

d) ⁶⁵Cu

e) ⁶³Co

Difficulty: Medium

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

Feedback: a) correct mass number, incorrect atomic number (added 1 rather than subtracted 1); b) correct answer; c) incorrect mass and atomic numbers; d) correct atomic number, incorrect mass number; e) incorrect mass and atomic numbers

14. Fission power produces unstable nuclides which have varying half-lives. One common product is cesium, with several different nuclides being produced. One nuclide that is problematic is ¹³⁷Cs which decays by emission with a half-life of 30.2 years. How many years will it take for 1.5 kg of ¹³⁷Cs to decompose to only 12 g of ¹³⁷Cs?

(If needed, use the following equation: )

a) 60.4

b) 181.2

c) 210.4

d) 213.4

e) 240.6

Difficulty: Medium

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

15. Positron emission and electron capture CANNOT be directly observed, but are indirectly observed by the

a) emission of visible light.

b) capture of the particles.

c) observation of high-energy electromagnetic radiation.

d) change in mass of the nuclide.

e) increase in half-life of the daughter nuclide.

Difficulty: Medium

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

16. Radioactive waste nuclides with short half-lives are usually less of a problem for disposal because they are quite active but only for a short time. For example, ¹³⁴ Cs has a half-life of 2.1 years. If initially there were 1.5 kg of ¹³⁴Cs, how much of this nuclide would be present in 14.7 years?

(If needed, use the following equation: )

a) 1.2 kg

b) 120 g

c) 12 g

d) 10 g

e) 14.7 g

Difficulty: Medium

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

17. Neutron-capture reactions are

a) endothermic, and only occur at high temperature.

b) exothermic, as neutron is attracted by strong nuclear force.

c) exothermic, as they are spontaneous.

d) result in stable reaction products.

Difficulty: Medium

Learning Objective: Describe how products are synthesized in induced nuclear reactions.

Section Reference: 21.3 Induced Nuclear Reactions

Feedback: a) true that it occurs at high temperature – but this is required to overcome activation barrier, not because process is endothermic; b) correct answer; c) true reaction is exothermic, but not all exothermic reactions are spontaneous; d) not necessarily true, the product of a neutron-capture reaction can undergo spontaneous decay

18. Which nuclei would undergo neutron capture and subsequent decay to produce ⁹⁹Tc, two γ particles and one β particle?

a) ¹⁰⁶Ag

b) ¹⁰⁷Ag

c) ⁹⁹Mo

d) ⁹⁸Mo

e) ⁹⁸Ru

Difficulty: Medium

Learning Objective: Describe how products are synthesized in induced nuclear reactions.

Section Reference: 21.3 Induced Nuclear Reactions

Feedback: a) two α particles rather than γ particles; b) two α particles rather than γ particles and did not account for neutron capture; c) did not account for neutron capture; d) correct answer; e) positron rather beta particle as reaction product

19. Neutron bombardment of nuclei typically requires lower energies than proton bombardment of nuclei. The energy difference is because

a) the strong nuclear force has a stronger attraction for the neutron/

b) gravity acts more strongly on the neutron/

c) the proton is attracted to the electron cloud/

d) the proton is repelled by the nucleus/

e) the electron cloud gives the proton a spiraling approach/

Difficulty: Easy

Learning Objective: Describe how products are synthesized in induced nuclear reactions.

Section Reference: 21.3 Induced Nuclear Reactions

20. When ⁶⁰Ni is bombarded with a proton, the unstable product undergoes a further nuclear reaction, ejecting an α particle to form a stable product. What is the identity of this stable product?

a) ⁵⁶Co

b) ⁵⁷Co

c) ⁵⁷Fe

d) ⁵⁵Fe

e) ⁶⁵Ga

Difficulty: Medium

Learning Objective: Describe how products are synthesized in induced nuclear reactions.

Section Reference: 21.3 Induced Nuclear Reactions

21. Seaborgium (Z= 106) can be synthesized by the bombardment of ²⁴⁹Cf with ¹⁶O. If four (4) neutrons are produced in the reaction, what is the mass number of the Sg nuclide?

a) 259

b) 260

c) 261

d) 262

e) 264

Difficulty: Medium

Learning Objective: Describe how products are synthesized in induced nuclear reactions.

Section Reference: 21.3 Induced Nuclear Reactions

22. A cyclotron could NOT be used to accelerate which of the following particles?

a) electron

b) proton

c) particle

d) neutron

e) ¹¹B⁵⁺

Difficulty: Medium

Learning Objective: Describe how products are synthesized in induced nuclear reactions.

Section Reference: 21.3 Induced Nuclear Reactions

23. Why do fission products tend to be radioactive?

a) They have excess electrons.

b) They have excess protons.

c) The neutron to proton ratio is high.

d) The neutron to proton ratio is low.

e) They emit gamma rays.

Difficulty: Easy

Learning Objective: Describe the fission process and the essential features of a fission reactor.

Section Reference: 21.4 Nuclear Fission

24. Which of the following is NOT a characteristic of fission reactions?

a) Only a few nuclides undergo fission.

b) Fission produces large amounts of energy.

c) Fission gives only a few nuclides as products.

d) Fission products are often radioactive.

e) Fission products always include one or more neutrons.

Difficulty: Easy

Learning Objective: Describe the fission process and the essential features of a fission reactor.

Section Reference: 21.4 Nuclear Fission

25. What is the definition of critical mass?

a) mass needed to start a nuclear bomb

b) mass with a neutron recapture ratio of 1

c) mass with a neutron recapture ratio less than 1

d) mass needed to be detected by airport security

e) mass needed to start a nuclear reactor

Difficulty: Easy

Learning Objective: Describe the fission process and the essential features of a fission reactor.

Section Reference: 21.4 Nuclear Fission

26. Which of the following are differences between a nuclear reactor and a nuclear fission weapon?

a) the neutron recapture ratio

b) the type of fuel

c) the method of concentrating the fuel

d) b and c

e) the kind of nuclear reaction occurring

Difficulty: Easy

Learning Objective: Describe the fission process and the essential features of a fission reactor.

Section Reference: 21.4 Nuclear Fission

27. All waste from a nuclear fission reactor

a) are solid and composed of the daughter products of the fission reaction.

b) can be safely disposed of as they are composed of low grade radioactive materials.

c) include thermal waste in the form of warm water.

d) result from melt down of the reactor.

e) is radioactive and poses a potential threat to the environment.

Difficulty: Easy

Learning Objective: Describe the fission process and the essential features of a fission reactor.

Section Reference: 21.4 Nuclear Fission

Feedback: Waste from nuclear reactor includes the spent fuel, but also thermal waste in the form of coolant water.

28. Successful operation of fission power plant requires

a) a fuel that will spontaneously decay via a radioactive process.

b) a moderator component to absorb neutrons and control the rate of the nuclear reactions.

c) a steam generator/turbine component that is fundamentally different than that found in coal driven power plants.

d) enriched grade uranium fuel.

e) a control component to limit the number neutrons available to trigger fission reactions.

Difficulty: Easy

Learning Objective: Describe the fission process and the essential features of a fission reactor.

Section Reference: 21.4 Nuclear Fission

Feedback: a) nuclear reaction is induced by bombardment of neutrons; b) moderator controls energy of neutrons but does not absorb them; c) electricity generating component of power plant is fundamentally the same as that for conventional power stations; d) not all fission reactors require enriched grade uranium, example CANDU uses natural grade; e) correct answer

29. How is electricity made from the energy released at a nuclear power plant?

a) via hot water

b) via steam

c) via heavy water

d) via refrigeration

e) via cooling towers

Difficulty: Easy

Learning Objective: Describe the fission process and the essential features of a fission reactor.

Section Reference: 21.4 Nuclear Fission

30. The main impediment to fusion

a) is the fact that these are first-order reactions, so they are kinetically slow.

b) fusion occurs only for a few very rare nuclides.

c) reacting nuclei must have high kinetic energies to penetrate electron clouds.

d) the fusion products are often radioactive.

e) reacting nuclei must have high kinetic energies to overcome electrical repulsion between positive particles.

Difficulty: Easy

Learning Objective: Describe the fusion process and the essential features of a fusion reactor.

Section Reference: 21.5 Nuclear Fusion

31. Fusion is important

a) as a current method of producing electricity.

b) for understanding the formation of the elements.

c) for triggering fission bombs.

d) b and c.

e) as an energy source for space programs.

Difficulty: Easy

Learning Objective: Describe the fusion process and the essential features of a fusion reactor.

Section Reference: 21.5 Nuclear Fusion

32. Which of the following is NOT a fusion reaction?

a) ¹H + ¹H 🡪 ²He + β

b) ¹H + ¹²C 🡪 ¹⁴N

c) ¹³C + ⁴He 🡪 ¹⁶O + ¹n

d) ²³⁵U + ¹n 🡪 ¹⁵³Nd + ⁸¹Ge + 3 ¹n

e) ⁵⁶Fe + ¹n 🡪 ⁵⁷Co + β

Difficulty: Easy

Learning Objective: Describe the fusion process and the essential features of a fusion reactor.

Section Reference: 21.5 Nuclear Fusion

33. Which of the following best explains why heavier elements don’t form in first-generation stars?

a) The concentration of reactants is not high enough.

b) The heavier elements are only made in a supernovae.

c) The spectrum of the star contains too much red.

d) Second generation stars are hotter.

e) There are free neutrons in a 1^st generation star.

Difficulty: Easy

Learning Objective: Describe the fusion process and the essential features of a fusion reactor.

Section Reference: 21.5 Nuclear Fusion

34. What is the primary cause of biological damage from radioactive emissions?

a) genetic mutation

b) loss of body fluids

c) sunburn from hair loss

d) ionization of molecules

e) opportunistic infection

Difficulty: Easy

Learning Objective: Explain the effects of ionizing radiation.

Section Reference: 21.6 Effects of Radiation

35. The REM unit

a) represents the total energy of radiation absorbed.

b) describes the effect of radiation on living humans.

c) is the amount of radiation necessary to treat food products.

d) accounts for the different properties of different types of radiation.

e) only applies to alpha emissions.

Difficulty: Easy

Learning Objective: Explain the effects of ionizing radiation.

Section Reference: 21.6 Effects of Radiation

36. Shielding is an important aspect of working with radioactive materials. Which of the following is the order of radiation type in order of increasing penetration?

a, , 

b

c

d

e)

Difficulty: Easy

Learning Objective: Explain the effects of ionizing radiation.

Section Reference: 21.6 Effects of Radiation

37. Which of the following is the order of radiation type as a function of increasing ionization potential?

a, , 

b

c

d

e)

Difficulty: Easy

Learning Objective: Explain the effects of ionizing radiation.

Section Reference: 21.6 Effects of Radiation

Feedback: Both penetration depth and ionization potential are important in assessing the extent to which radiation will be hazardous.

38. Radiation treatment for cancer is effective because

a) cancer cells absorb more radiation than normal cells.

b) radioactive isotopes bind to tumours.

c) radiation has deleterious effects on rapidly dividing cells.

d) radiation can be precisely focused on cancerous cells.

e) it is less costly than other treatments.

Difficulty: Easy

Learning Objective: Explain the effects of ionizing radiation.

Section Reference: 21.6 Effects of Radiation

39. What radioactive particle do you need to be concerned about that can go through clothing but NOT through your body?

a) alpha

b) beta positive

c) beta negative

d) gamma

e) neutron

Difficulty: Medium

Learning Objective: Explain the effects of ionizing radiation.

Section Reference: 21.6 Effects of Radiation

40. Listed below are the mass numbers for several isotopes of cobalt, along with their mode(s) of decay and the half-lives. Which of them is best suited for use as a tracer?

(If needed, use the following equations: )

a) 53, ⁺ (1.46 min)

b) 55, ⁺ (17.5 hr)

c) 56, EC (77.7 day)

d) 58, ⁺ (70.9 dy)

e) 60, ^- (5.272 yr)

Difficulty: Easy

Learning Objective: Explain some practical applications of radioactivity.

Section Reference: 21.7 Applications of Radioactivity

41. Which of the following factors limit the radio-dating techniques?

a) the half-life of the isotope

b) the amount of background radiation

c) the quantity of sample

d) all of the above

e) none of the above

Difficulty: Easy

Learning Objective: Explain some practical applications of radioactivity.

Section Reference: 21.7 Applications of Radioactivity

42. Melvin Calvin received a Noble Prize for unravelling the reaction sequence of the production of sugar in plants. How was he able to do this?

a) using tritium to slow the reactions down

b) taking multiple x-rays as a plant is growing

c) using a radioactive tracer to follow the carbon throughout the plant

d) growing a plant by only using human breath

e) using Carbon-14 dating

Difficulty: Easy

Learning Objective: Explain some practical applications of radioactivity.

Section Reference: 21.7 Applications of Radioactivity

43. Typically how old can an artifact found in an archeological dig be and still allow you to use Carbon-14 dating to analyze its age? (¹⁴C, t_1/2 = 5730 years.)

(If needed, use the following equations: )

a) 1 half-life

b) 2 half-lives

c) 4 half-lives

d) 5 half-lives

e) can use it to determine the age of anything.

Difficulty: Easy

Learning Objective: Explain some practical applications of radioactivity.

Section Reference: 21.7 Applications of Radioactivity

44. Your lab is sent an ash sample from an archeological dig that you determine has a Carbon-14 activity of 1200 counts per minute. A piece of ash taken from your fireplace has a Carbon-14 activity of 3600 counts per minute. How old was the campsite where the ash was taken from? (¹⁴C has a half-life of 5730 years.)

a) 5700 years

b) 9100 years

c) 11,500 years

d) 17,200 years

e) 24,000 years

Difficulty: Medium

Learning Objective: Explain some practical applications of radioactivity.

Section Reference: 21.7 Applications of Radioactivity

ESSAY QUESTIONS

45. Calculate and compare the binding energies per nucleon of ¹⁹F (18.998403 amu) and ²³⁹Pu (239.052157 amu). Does this information suggest which nuclide will be more susceptible to fission?

(If needed, use the following equations: E = mc² c = 3.0 x 10⁸m/s E = Δm(8.988 x10¹⁰ kJ/g)

mass_proton = 1.007276 g/mol mass_neutron = 1.008665 g/mol mass_electron = 0.0005486)

Difficulty: Medium

Learning Objective: Explain the forces that hold nuclei together.

Section Reference: 21.1 Nuclear Stability

46. The atomic masses of two isotopes of B are 12.0143 and 11.00931. Calculate the binding energy for each isotope and predict which of the two is more abundant.

(If needed, use the following equations: E = mc² c = 3.0 x 10⁸m/s E = Δm(8.988 x10¹⁰ kJ/g)

mass_proton = 1.007276 g/mol mass_neutron = 1.008665 g/mol mass_electron = 0.0005486)

Difficulty: Hard

Learning Objective: Explain the forces that hold nuclei together.

Section Reference: 21.1 Nuclear Stability

Feedback: Both B isotopes have negative binding energy; however the per nucleon energy is greater of ¹¹B giving it higher abundance.

47. What is the binding energy per nucleon for ²³⁸U in kJ mol^-1 (molar mass: 238.05078 g mol^-1)?

(If needed, use the following equations: E = mc² c = 3.0 x 10⁸m/s E = Δm(8.988 x10¹⁰ kJ/g)

mass_proton = 1.007276 g/mol mass_neutron = 1.008665 g/mol mass_electron = 0.0005486)

Difficulty: Easy

Learning Objective: Explain the forces that hold nuclei together.

Section Reference: 21.1 Nuclear Stability

Feedback: Watch out for units.

48. If the binding energy per nucleon for ²³⁸U in kJ mol^-1 is –7.30x10⁸kJ mol^-1, what is the molar mass of ²³⁸U?

(If needed, use the following equations: E = mc² c = 3.0 x 10⁸m/s E = Δm(8.988 x10¹⁰ kJ/g)

mass_proton = 1.007276 g/mol mass_neutron = 1.008665 g/mol mass_electron = 0.0005486)

Difficulty: Medium

Learning Objective: Explain the forces that hold nuclei together.

Section Reference: 21.1 Nuclear Stability

Feedback: working the standard problem backwards

49. How much water, initially at 25°C (in kg) could be vapourized by the conversion of 50 g of matter to energy? [ΔH_vap (H₂O) = 44 kJ/mol]

(If needed, use the following equations: E = mc² c = 3.0 x 10⁸m/s E = Δm(8.988 x10¹⁰ kJ/g)

mass_proton = 1.007276 g/mol mass_neutron = 1.008665 g/mol mass_electron = 0.0005486)

Difficulty: Hard

Learning Objective: Explain the forces that hold nuclei together.

Section Reference: 21.1 Nuclear Stability

50. A sample of ¹³³Xe is captured and a Geiger counter shows activity of 1400 counts per minute. Ten and a half (10.5) days later the counter reads 350 counts. What is the half-life of this nuclide?

(If needed, use the following equation: )

Difficulty: Hard

Learning Objective: Describe nuclear decay processes and calculate rates of decay.

Section Reference: 21.2 Nuclear Decay

51. Bombarding a nuclide with a  photon ( ray) gives a proton, a neutron and ²⁹Si. What is the identity of the parent nuclide?

Difficulty: Easy

Learning Objective: Describe how products are synthesized in induced nuclear reactions.

Section Reference: 21.3 Induced Nuclear Reactions

52. When ²³⁸U is bombarded with a particle, the product is ²³⁹Pu and three neutrons. What is the identity of the particle?

Difficulty: Medium

Learning Objective: Describe how products are synthesized in induced nuclear reactions.

Section Reference: 21.3 Induced Nuclear Reactions

53. ²⁴²Cm is synthesized from bombarding ²³⁹Pu with  particles. How many neutrons are released in this process?

Difficulty: Medium

Learning Objective: Describe how products are synthesized in induced nuclear reactions.

Section Reference: 21.3 Induced Nuclear Reactions

54. When ²³⁵U (235.043924 amu) captures a neutron, one set of fission products is ⁹⁰Rb (89.914811 amu) and ¹⁴⁴Cs (143.93193 amu). Balance the reaction and calculate the energy released when 1 mole of ²³⁵U undergoes this fission reaction.

(If needed, use the following equations: E = mc² c = 3.0 x 10⁸m/s E = Δm(8.988 x10¹⁰

kJ/g) mass_proton = 1.007276 g/mol mass_neutron = 1.008665 g/mol mass_electron = 0.0005486)

Difficulty: Hard

Learning Objective: Describe the fission process and the essential features of a fission reactor.

Section Reference: 21.4 Nuclear Fission

55. When ²³⁵U (235.043924 amu ) captures a neutron, one set of fission products is ⁹²Sr (91.910944 amu) and ¹⁴²Xe (141.92963 amu). Balance the reaction and calculate the energy released when 1 mole of ²³⁵U undergoes this fission reaction.

(If needed, use the following equations: E = mc² c = 3.0 x 10⁸m/s E = Δm(8.988 x10¹⁰

kJ/g) mass_proton = 1.007276 g/mol mass_neutron = 1.008665 g/mol mass_electron = 0.0005486)

Difficulty: Hard

Learning Objective: Describe the fission process and the essential features of a fission reactor.

Section Reference: 21.4 Nuclear Fission

56. What is the energy release associated per mole of fuel when ²⁷Al (mass = 26.98153 amu) is bombarded by an He (4.00260 amu) neutron to form ³⁰P (29.96507 amu) and one neutron?

(If needed, use the following equations: E = mc² c = 3.0 x 10⁸m/s E = Δm(8.988 x10¹⁰ (–kJ/g) mass_proton = 1.007276 g/mol mass_neutron = 1.008665 g/mol mass_electron = 0.0005486)

Difficulty: Medium

Learning Objective: Describe the fission process and the essential features of a fission reactor.

Section Reference: 21.4 Nuclear Fission

57. Carbon-12 can undergo fusion reaction to form ²⁰Ne, ²³Na or ²³Mg. In each case a small nuclear particle is formed. Identify the particles formed.

Difficulty: Easy

Learning Objective: Describe the fusion process and the essential features of a fusion reactor.

Section Reference: 21.5 Nuclear Fusion

58. What is the energy change (in kJ) in the synthesis of 1 mole of (31.972070 amu) from
16(2.0140 amu)?

Difficulty: Medium

Learning Objective: Describe the fusion process and the essential features of a fusion reactor.

Section Reference: 21.5 Nuclear Fusion

59. What is the energy change (in kJ) and in what form is it released when ¹²C (12 amu) and He(4.00260) undergo fusion to form ¹⁶O (15.994915)?

Difficulty: Medium

Learning Objective: Describe the fusion process and the essential features of a fusion reactor.

Section Reference: 21.5 Nuclear Fusion

Feedback: Determine the mass defect and energy released using E= Δmc².

60. How much energy is released when oxygen and carbon form magnesium as shown below?

¹²C + ¹⁶O 🡪 ²⁴Mg + ⁴He

Difficulty: Hard

Learning Objective: Describe the fusion process and the essential features of a fusion reactor.

Section Reference: 21.5 Nuclear Fusion

61. A particular isotope of cobalt, used as a tracer, has a half-life of 17.5 hours. What percentage of Co remains after 5 days?

(If needed, use the following equations: )

Difficulty: Easy

Learning Objective: Explain some practical applications of radioactivity.

Section Reference: 21.7 Applications of Radioactivity

62. Argon dating indicates a particular rock sample is 1x10⁹ years old. If t_1/2 for the decay of ⁴⁰K to ⁴⁰Ar is 1.28x10⁹ years, what % of the original potassium is remaining in the sample?

(If needed, use the following equations: )

Difficulty: Medium

Learning Objective: Explain some practical applications of radioactivity.

Section Reference: 21.7 Applications of Radioactivity

63. Argon dating indicates a particular rock sample is 5x10⁹ years old. If t_1/2 for the decay of ⁴⁰K to ⁴⁰Ar is 1.28x10⁹ years, what % of the original potassium in the sample has decayed?

(If needed, use the following equations: )

Difficulty: Medium

Learning Objective: Explain some practical applications of radioactivity.

Section Reference: 21.7 Applications of Radioactivity

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