Page 444 - Schaum's Outline of Theory and Problems of Applied Physics

CHAP. 34] ATOMIC PHYSICS 429

Answers to Multiple-Choice Questions

34.1. (d) 34.9. (b)

34.2. (b) 34.10. (a)

34.3. (b) 34.11. (d)
34.4. (b) 34.12. (a), (b)

34.5. (c) 34.13. (c)

34.6. (c) 34.14. (d)
34.7. (a) 34.15. (c)

34.8. (b), (c) 34.16. (c)

Answers to Supplementary Problems

34.1. The uncertainties in the position and momentum of an object much larger than an elementary particle are so small
compared with its dimensions and momentum as to be undetectable.
34.2. The lower the ionization energy of a metal, the more easily one of its electrons can be detached in a chemical reaction
and hence the more active it is. Thus potassium, whose ionization energy is 4.3 eV, is more active chemically than
zinc, whose ionization energy is 9.4 eV.

34.3. (a) Continuous emission spectrum as described in Chapter 22 (b) Emission line spectrum
(c) Absorption line spectrum

34.4. The presence of the spectral lines of a particular element in the spectrum of the sun or a star means that this element
must be present there.

34.5. A hydrogen sample contains a great many atoms, each of which can undergo a variety of transitions between energy
levels.

34.6. The orbit must be one de Broglie wavelength in circumference; or equivalently, the orbital angular momentum of
the electron must be equal to h/(2π).
34.7. The light waves from a laser are coherent, that is, they are exactly in phase with one another.

34.8. 2 × 10 −34 m

34.9. 1.51 eV
34.10. No, because the uncertainty principle limits (mv) x to a minimum of 1.05 × 10 −34 J·s.

34.11. (a)1.05 × 10 −25 kg·m/s (b)3.3 × 10 −24 J = 0.21 MeV

34.12. (a)3.68 × 10 −63 m (b)2.56 × 10 74 (c)No

34.13. 0.85 eV