A star shows weak hydrogen Balmer lines but strong lines of neutral sodium.Which is a likely explanation for this phenomenon?
A) This particular star contains no hydrogen.
B) The hydrogen has been ionized.
C) The hydrogen is not receiving enough energy to populate the n = 2 level required for Balmer transitions.
D) The sodium lines are masking the hydrogen lines because these occur at the same wavelengths.

Question

Quizplus · Accepted Answer

The weak Balmer lines indicate that the hydrogen atoms in the star are not having enough energy to populate the n=2 level required for Balmer transitions. The strong lines of neutral sodium suggest the presence of sodium atoms in the star's atmosphere. We can rule out options A and B as they suggest a lack of hydrogen or ionized hydrogen, respectively, which are not consistent with the weak Balmer lines. Option D is also unlikely as the sodium lines would only mask the Balmer lines if they occur at precisely the same wavelengths, which is not generally the case.

A Star Shows Weak Hydrogen Balmer Lines but Strong Lines