Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space?
A)The cloud is extremely hot.
B)The cloud is visible primarily because it reflects light from nearby stars.
C)The cloud is cool and very dense,so that you cannot see any objects that lie behind it.
D)The cloud is cool and lies between you and a hot star.

Question

Quizplus · Accepted Answer

An absorption line spectrum is seen when a cool cloud of gas lies between the observer and a hot star. The gas in the cloud absorbs certain wavelengths of light from the star, resulting in dark absorption lines in the spectrum.

Which of the Following Conditions Lead You to See an Absorption