Quiz 10 Section: Name:

Quiz 10
Phys 222, Fall 2014
Problem 1.(2 points.) The process that produces photons of the same frequency,
phase, direction and polarization is
A) constructive Interference.
B) spontaneous emission.
C) absorption.
D) stimulated emission.
E) pumping.
Problem 2.(1.5 points.) In an atom, how many electron states are in the n=2 shell?
Problem 3.(1.5 points.) Violet light is able to eject electrons from the surface of
potassium metal, whereas red light cannot. Why?
A) The intensity of violet light is always greater than that of red light.
B) Red light is more efficiently absorbed by air and therefore does not reach the metal.
C) The wavelength of violet light is greater than that of red light and its energy is
therefore spread over more electrons, giving it more targets.
D) The frequency of red light is lower than that of violet light and its photon energy
is not sufficient to eject electrons.
Extra credits(2 points.) Why did the chicken cross the road?