Page 464 - Schaum's Outline of Theory and Problems of Applied Physics

CHAP. 36] NUCLEAR PHYSICS 449

36.11. The most penetrating of the following radiations is
(a) an alpha particle (c) a positron
(b) an electron (d) a gamma ray

36.12. The half-life of a radionuclide equals
(a) half the time needed for a sample to completely decay
(b) half the time a sample can be kept before it starts to decay
(c) the time needed for half a sample to decay
(d) the time needed for the rest of a sample to decay once half of it has already decayed

36.13. During the decay of a radionuclide, its half-life
(a) decreases (c) increases
(b) does not change (d) any of the above, depending on the nuclide
20
36.14. The sum of the masses of 10 protons and 10 neutrons is 0.172 u more than the mass of a Ne nucleus. The binding
10
energy per nucleon in this nucleus is
(a) 8.6 × 10 −3 eV (c) 16.0 MeV
14
(b) 8.0 MeV (d) 7.7 × 10 eV
36.15. When the uranium isotope 234 U undergoes alpha decay, the result is the nuclide
92
(a) 230 Th (c) 232 Ra
90 88
(b) 230 U (d) 230 Ra
92 88
87
36.16. When the strontium isotope Sr undergoes gamma decay, the result is the nuclide
38
(a) 87 Rb (c) 87 Y
37 39
(b) 87 Sr (d) 83 Kr
38 36
64
64
36.17. The copper isotope Cu decays into the nickel isotope Ni by emitting
29 28
(a) an electron (c) an alpha particle
(b) a positron (d) a gamma ray
36.18. A certain radionuclide has a half-life of 12 h. Starting from 1.00 g of the nuclide, the amount left after 2 d will be
(a) 0 (c) 0.16 g
(b) 0.0625 g (d) 0.25 g
36.19. After 2 h has elapsed, 1/16 of the original quantity of a certain radionuclide remains undecayed. The half-life of
this radionuclide is
(a) 15 min (c) 45 min
(b) 30 min (d) 60 min

Supplementary Problems

36.1. Which of the fundamental interactions has the least significance in nuclear physics?

36.2. In experiments involving nuclear fusion, magnetic fields rather than solid containers are used to confine atomic
nuclei that are to react. Why?

36.3. What are the similarities and differences between nuclear fission and nuclear fusion?