Page 466 - Schaum's Outline of Theory and Problems of Applied Physics

CHAP. 36] NUCLEAR PHYSICS 451

Answers to Supplementary Problems

36.1. The gravitational interaction

36.2. In such experiments, the nuclei form a gas at very high temperature that is called a plasma. A plasma would be
cooled upon contact with a solid container, and atoms of the container would also be dislodged and enter the plasma,
where they might affect the reaction unfavorably. It is not likely that the container would actually melt, since the
total internal energy of the plasma, as distinguished from its temperature, is not very great.

36.3. In fission, a large nucleus splits into smaller ones; in fusion, two small nuclei join to form a larger one. In both
processes, the products of the reaction have less mass than the original nucleus or nuclei, with the missing mass
being released as energy.

36.4. The number of protons and neutrons in its nucleus determines the mass of an atom, and the number of electrons in
the electron cloud surrounding the nucleus governs its chemical behavior.

36.5. 7p,8n;17p,18n;30p,34n;80p, 120n

36.6. 10.81 u
36.7. (a) 7.71 MeV (b) 2.57 MeV

36.8. (a) 298 MeV (b) 8.5 MeV
36.9. 41.9586 u

1
2
36.10. 17 8 O; n; H
0
1
5
14
36.11. (a) 9 × 10 J (b) 2.25 × 10 tons
36.12. 7.27 MeV
36.13. Helium and radon cannot be combined to form radium, nor can radium be broken down into helium and radon by
chemical means.
36.14. Z and A are unchanged, but the actual mass decreases in proportion to the energy lost.

36.15. 206 Pb
82
10
10
36.16. (a) 1.35 × 10 yr (b) 1.8 × 10 yr
36.17. (a) 90 Y (b) 6.25 percent
39