The Doppler effect from the back-and-forth motion of atoms in a glowing discharge tube tends to make the spectral lines slightly
A)thicker.
B)thinner.
C)more numerous.
D)none of these

Question

Quizplus · Accepted Answer

The Doppler effect causes broadening of spectral lines due to the motion of atoms towards or away from the observer, making the lines appear thicker.

The Doppler Effect from the Back-And-Forth Motion of Atoms in a Glowing