Quiz 8 (Chapter 9) Study GuideName:______Period:____

1. When a heavy nucleus decays, it may emit:

a. alpha particleb. gamma raysc. beta particlesd. all of the above

2. A neutron decays to form a proton and a(an):

a. alpha particleb. gamma raysc. beta particlesd. emitted neutron

3. The process in which a heavy nucleus splits into two lighter nuclei is called:

a. fissionb. alpha decayc. fusiond. a chain reaction

4. / Symbol / Definition
Alpha decay
Beta decay

5. Why do gamma rays have no mass at all?

6. For the fission process, how is critical mass important in a chain reaction?

7. How does nuclear fusion account for the energy produced in stars?

8. How can nuclear power plants produce substantial amounts of energy while consuming very little fuel?

a. radioactive isotopes release a large amount of chemical energy

b. when large atoms break apart, some of their mass is converted to energy

c. the bonds between uranium atoms are very strong and release energy when they are broken

d. a significant amount of energy is released when two atoms come together to form one larger atom

9. What is the half-life of a 120g sample of Nitrogen-16 that decays to 15g of Nitrogen-16 in 21.6 seconds?

10. If the half life is 9.1 days, how long will it take a 50g sample to decay to 6.25 g?

11. If a 600g sample decays to 75g in 50,000 years, what is the half-life?

12. How long will it take a 660g sample to decay to one-fourth its original mass?

13. If the half-life of uranium-235 is 7.04 x 108 years and 12.5g of uranium-235 after 2.82 x 109 years, how much of the radioactive isotope was in the original sample?

14. Potassium-42 has a half life of 12.4 hours. How much of an 848g sample will be left after 62 hours?

15. Carbon-14 has a half-life of 5730 years. How much of a 144g sample will remain

after 1.719 x 104 years?

16. A strong nuclear force

a. attracts protons to electrons

b. holds molecules together

c. holds the atomic nucleus together

d. attracts electrons to neutrons

17. The amount of energy produced during nuclear fission is related to

a. the temperature in the atmosphere during nuclear fission

b. the masses of the missing nuclei and particles released

c. the volume of the nuclear reactor

d. the square of the speed of sound

18. Which is NOT a use for radioactive isotopes?

a. as tracers for diagnosing disease

b. as an additive to paints to increase their durability

c. as a way of treating forms of cancer

d. as a way to study biochemical processes in plants

19. Identify X: ______What type of decay? ______

209Ac AX + 4He

85 Z 2

20.Identify X: ______What type of decay? ______

222Rn AX + 4He

86 Z 2

21. Identify X: ______What type of decay? ______

14C  A X + 0e

6 Z -1

22. Identify X: ______What type of decay? ______

210Bi A X + 0e

83 Z -1

22. Identify X: ______What type of decay? ______

227Ac  227 Th + AX

89 90 Z

23. Identify X: ______What type of decay? ______

149Sm  145 Nd + AX

62 60 Z