Suppose you want to know the chemical composition of a distant star. Which piece of information is most useful to you?
A) The wavelengths of spectral lines in the star's spectrum
B) The peak energy of the star's thermal radiation
C) The Doppler shift of the star's spectrum
D) Whether the star's spectrum has more emission lines or more absorption lines

Question

Quizplus · Accepted Answer

The wavelengths of spectral lines in the star's spectrum can provide information about the chemical composition of the star. Different elements absorb and emit light at specific wavelengths, so by looking at the spectrum of the star, we can identify the elements present in its atmosphere. The other options may provide information about the star's motion and temperature, but they do not directly relate to its chemical composition.

Suppose You Want to Know the Chemical Composition of a Distant