A shift in the position of an emission line of an element toward the red or blue is produced by ____.
A) atoms that become ionized
B) electrons that transfer from a high energy level to a low energy level
C) electrons that transfer from a low energy level to a high energy level
D) the intensity of agitation of atoms in a hot gas
E) the motion of an object toward or away from the observer

Question

Quizplus · Accepted Answer

The shift in the position of an emission line toward the red (redshift) or blue (blueshift) end of the spectrum is caused by the Doppler effect, which occurs due to the motion of an object toward or away from the observer. This effect is not directly related to the ionization of atoms, the energy level transitions of electrons, or the intensity of agitation of atoms in a hot gas.

A Shift in the Position of an Emission Line of an Element