Chapter 19: Nuclear Chemistry Student:_______________________________________________________________________

1. Elements above what number are all radioactive?

(A) 53 (B) 64 (C) 72 (D) 83

2. What is the name of the process in which a nucleus is bombarded by neutrons, protons, or other nuclei?

(A) Fission (B) Radioactive decay (C) Nuclear transmutation (D) Nuclear binding

3. Which of the following is correctly matched with symbol and particle?

(A) 11 p; positron

(B) 01 n; alpha particle

(C) 1-0 e; positron

(D) 1

0+

e; positron

4. Which of the following statements is true?

(A) Chemical reactions can change one type of atom into another. (B) Nuclear reactions are accompanied by very small changes in energy. (C) Chemical reactions involve changes in elementary particles. (D) Nuclear reactions can involve bombarding two nuclei together.

5. When atoms of nitrogen–14 are bombarded with alpha particles, what product(s) are formed?

(A) Oxygen–17 and a proton (B) Nitrogen–18 (C) Chlorine–17 and a neutron (D) Neon–20

6. Polonium–212 decays through alpha emission. What product is formed besides the alpha particle?

(A) Barium–137 (B) Lead–208 (C) Bismuth–209 (D) Thallium–206

7. The principal factor determining nuclear stability is

(A) the electron: proton ratio (B) the neutron: positron ratio (C) the neutron: proton ratio (D) the electron: neutron ratio

8. Which of the following numbers are considered extra stable in terms of neutron or proton number?

(A) 24 (B) 50 (C) 92 (D) 124

9. The general term for protons and neutrons in the nucleus is

(A) positrons (B) nucleons (C) isotopes (D) plasmas

10. The difference between the mass of an atom and the sum of the masses of its neutrons, protons, and electrons is called

(A) mass defect (B) nuclear defect (C) critical mass (D) fission threshold

11. To calculate nuclear binding energy, what number must be known?

(A) mass of an electron (B) mass of light (C) critical mass (D) mass defect

12. Calculate the mass defect of carbon–12, given the mass of carbon–12 is 12.0107 amu, the neutron is 1.008665 amu and a hydrogen atom is 1.007825 amu.

(A) –0.001 amu (B) –0.023 amu (C) –0.03 amu (D) –0.0882 amu

13. Calculate the nuclear binding energy per nucleon of carbon–14, given the mass of carbon–14 is 14.003241 amu, the neutron is 1.008665 amu and a hydrogen atom is 1.007825amu.

(A) 1.21 × 10–12 J (B) 1.69 × 10–11 J (C) 1.02 × 1016 J (D) 1.13 J

14. Which order of kinetics does radioactive decay obey?

(A) Zero (B) 1st (C) 2nd (D) 3rd

15. In an alpha decay, the number of protons in the parent atom

(A) goes up by 1 (B) goes up by 2 (C) doesn’t change (D) goes down by 2

16. In a beta decay, the number of protons in the parent atom

(A) goes up by 1 (B) goes up by 2 (C) doesn’t change (D) goes down by 1

17. The first stable isotope formed as uranium–238 decays is

(A) Bismuth–209 (B) Lead–206 (C) Thorium–232 (D) Radium–226

18. What is formed in the transmutation process when uranium–238 is bombarded with a neutron and a beta particle is released?

(A) Pu–239 (B) Np–239 (C) Am–240 (D) Cm–242

19. Which of the following statements is true?

(A) Uranium–235 is more stable than uranium–238. (B) The first major application of nuclear fission was the atomic bomb. (C) Breeder reactors use the fusion process. (D) Nuclear fission involves a net absorption of energy.

20. Routine analysis indicated what mine in Africa was the location of a natural fission reactor?

(A) Pierrelatte (B) Chernobyl (C) Gabon (D) Oklo

Free Response

21. Iodine–131 is used in medicine to study the thyroid gland. I–131 decays by emission.

(a) Write a nuclear equation representing the decay of I–131.

(b) The I–131 isotope has a half-life of 8 days. If a dose contains 2.0 × 10–4 g of I–131, how many days would pass before the amount of I–131 was reduced to 2.5 × 10–5 g?

22. Potassium–40 can undergo electron capture as a decay mode. This decay mode is useful to date some minerals.

(a) Write a nuclear equation representing the decay of K–40 by electron capture.

(b) The half life, t1/2 of K–40 is 1.2 × 109 yr.

(i) Determine the value of the rate constant, k, for the decay.

(ii) How long will it take for the amount of K–40 in a sample to go from 7.5 ×10–4 g to 2.6 × 10–4 g?

(c) What happens to the protons and neutrons in the nucleus in electron capture?