Page 465 - Schaum's Outline of Theory and Problems of Applied Physics

450 NUCLEAR PHYSICS [CHAP. 36

36.4. What parts of its structure are chiefly responsible for an atom’s mass and for its chemical behavior?
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64
15
36.5. State the numbers of protons and neutrons in each of the following nuclei: N, Cl, Zn, 200 Hg.
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30
7
17
10
11
36.6. Ordinary boron is a mixture of 20 percent of the B isotope and 80 percent of the B isotope. The atomic masses
5
5
of these isotopes are, respectively, 10.013 and 11.009 u. Find the atomic mass of ordinary boron.
3
36.7. The atomic mass of He is 3.01603. (a) What is its binding energy? (b) What is its binding energy per nucleon?
2
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36.8. The atomic mass of Cl is 34.96885 u. (a) What is its binding energy? (b) What is its binding energy per nucleon?
17
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36.9. The binding energy of Ca is 361.7 MeV. Find its atomic mass.
20
36.10. Complete the following nuclear reactions:
4
14 N + He → H + ?
1
7 2 1
11 1 11 C + ?
1
5 B + H → 6
1
7
6 Li + ? → Be + n
3 4 0
36.11. When 235 U undergoes fission, about 0.1 percent of the original mass is released as energy. (a) How much energy is
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released by an atomic bomb that contains 10 kg of 235 U? (b) When 1 ton of TNT is exploded, about 4 × 10 Jis
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released. How many tons of TNT are equivalent in destructive power to the above bomb?
4
36.12. In some stars three He nuclei fuse in sequence to form a 12 6 C nucleus (m = 12.000000 u). How much energy is
2
liberated each time this happens?
36.13. Radium spontaneously decays into the elements helium and radon. Why is radium itself considered an element and
not simply a chemical compound of helium and radon?
36.14. What happens to the atomic number and mass number of a nucleus that emits a gamma-ray photon? What happens
to its mass?
36.15. The uranium isotope 238 U decays into a stable lead isotope through the successive emission of eight alpha particles
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and six electrons. What is the symbol of the lead isotope?
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36.16. The half-life of 238 U against alpha decay is 4.5 × 10 yr. (a) How long does it take for seven-eighths of a sample of
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this isotope to decay? (b) For fifteen-sixteenths to decay?
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90
36.17. The half-life against beta decay of the strontium isotope Sr is 28 yr. (a) What does Sr become after beta decay?
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38
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(b) What percentage of a sample of Sr will remain undecayed after 112 yr?
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Answers to Multiple-Choice Questions
36.1. (d) 36.6. (b) 36.11. (d) 36.16. (b)
36.2. (a) 36.7. (c) 36.12. (c) 36.17. (b)
36.3. (a) 36.8. (c) 36.13. (b) 36.18. (b)
36.4. (a) 36.9. (c) 36.14. (b) 36.19. (b)

36.5. (b) 36.10. (d) 36.15. (a)