Page 442 - Schaum's Outline of Theory and Problems of Applied Physics

CHAP. 34] ATOMIC PHYSICS 427

34.6. A photon is emitted by an atom when one of the atom’s electrons
(a) leaves the atom
(b) collides with another of its electrons
(c) shifts to a lower energy level
(d) shifts to a higher energy level

34.7. The wavelengths in the bright-line emission spectrum of an element are
(a) characteristic of the particular element
(b) the same for all elements
(c) evenly distributed throughout the visible spectrum
(d) different from the wavelengths in its dark-line absorption spectrum

34.8. When an atom absorbs a photon of light, which one or more of the following can happen?
(a) An electron shifts to a state of smaller principal quantum number.
(b) An electron shifts to a state of higher principal quantum number.
(c) An electron leaves the atom.
(d) An X-ray photon is emitted.

34.9. The sun’s spectrum consists of a bright background crossed by dark lines. This suggests that the sun has a
(a) hot interior surrounded by a hot atmosphere
(b) hot interior surrounded by a cool atmosphere
(c) cool interior surrounded by a hot atmosphere
(d) cool interior surrounded by a cool atmosphere

34.10. A quantum number is not associated with an atomic electron’s
(a) mass (c) spin
(b) energy (d) orbital angular momentum

34.11. The exclusion principle states that no two electrons in an atom can have the same
(a) velocity (c) spin
(b) orbit (d) set of quantum numbers

34.12. Which one or more of the following events cannot raise an atom from its ground state to an excited state?
(a) spontaneous emission of a photon
(b) induced emission of a photon
(c) absorption of a photon
(d) a collision with another atom

34.13. The operation of the laser is based on which one or more of the following?
(a) the uncertainty principle
(b) the exclusion principle
(c) induced emission of radiation
(d) interference of matter waves

34.14. The waves emitted by a laser do not
(a) all have the same wavelength
(b) emerge in step with one another
(c) form a narrow beam
(d) have higher photon energies than waves of the same frequency from an ordinary source
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34.15. An electron with a velocity of 1.5 × 10 m/s has a de Broglie wavelength of
(a)9.1 × 10 −57 m (c)4.9 × 10 −11 m
(b)6.5 × 10 −18 m (d)4.9 × 10 −10 m