Name ______

Ch 21 · Nuclear Chemistry

1. Show how a, b, and g rays each behave when they pass through an electric field. Use the diagram below to illustrate your answer. What direction does each particle travel and what bending occurs.

Match the rays with the following ideas. Each ray may be used once, more than once, or not at all.

a) alpha b) beta c) gamma

___ 2. Two protons and two neutrons ___ 7. High speed electron

___ 3. a ___ 8. He

___ 4. Higher energy than x-rays ___ 9. b-

___ 5. Helium nucleus ___ 10. e

___ 6. Most easily stopped.

Complete the following nuclear equations:

11. Co + n ® Mn + c

12. C ® N + c

13. Mo ® c + e + g

14. (alpha decay of U-235)

15. K + c ® Ar

/ 16. What is the half life of the graphed material? ____17. What mass of radioisotope will remain after 12.0 hours? _____

18. Plot the data for a substance with a half-life of 1.5 hours, beginning with 100 grams.

19. Lr-257 has a half life of 8 seconds. What % of a sample will remain 32 seconds after it is made?

20. Na-24 has a half life of 15 hours. What is the rate constant, k, for Na-24 (include units)?

21. A 64 gram sample of I-131 is tested after 40 days and is found to contain only 2 grams of I-131. What is the half life of I-131?

22. The sum of 2 protons, 2 neutrons, and 2 electrons is 4.0322980 amu; however, the measured mass of He is only 4.00260 amu. What happens to this mass?

Match the types of nuclear changes with the equations:___23. Fission

(occurs in nuclear reactors & atomic bombs)

___24. Fusion

(occurs in the Sun & hydrogen bombs)

___25. Neutron Bombardment

___26. Electron Capture /

27. a) Iodine-130 has a half-life of 8.0 days. What is the value of the rate constant, k, for I-130?

b) What percentage of a sample of I-130 remains after 35 days?

c) What sort of decay would you predict for I-130? ______(alpha, beta, positron)

28. A wooden artifact has a carbon 14 activity of 24.9 counts per minute as compared with an activity of 32.5 counts per minute for a standard from 0 age. Knowing the half life of C-14 is 5715 years, determine the age of the artifact. Show your work!!

29. Design an experiment where you use radioactive Fe-59 (a beta emitter with half life of 44.5 days) to determine the extent to which rabbits are able to convert a particular iron compound in their diet into blood hemoglobin, which contains iron atoms.