If light from a hot, dense star passes through a cool cloud of gas,
A) the atoms of the gas cloud will add energy to the overall spectrum, enhancing it at specific wavelengths to produce emission lines.
B) the cool gas will not affect the spectrum of the star because cool atoms cannot absorb light.
C) the whole spectrum will be reduced in intensity.
D) only specific wavelengths of light will be removed from the spectrum.

Question

Quizplus · Accepted Answer

When light from a hot, dense star passes through a cool cloud of gas, the atoms in the cool gas absorb light at specific wavelengths corresponding to the energy differences between their electron energy levels. This absorption removes light at these wavelengths from the spectrum, creating dark lines known as absorption lines. This does not enhance the spectrum or add energy to it, nor does it reduce the entire spectrum's intensity.

If Light from a Hot, Dense Star Passes Through a Cool