Question

describing how astronomers use the electromagnetic spectrum
which part of the electromagnetic spectrum helped astronomers understand that the crab nebula contains hydrogen?
o gamma rays
o microwaves
o radio waves
o visible light

Explanation:

Astronomers use spectroscopy of visible - light to identify elements. Hydrogen has specific spectral lines in the visible part of the electromagnetic spectrum, known as the Balmer series. These spectral lines are unique signatures of hydrogen and allow astronomers to detect its presence in celestial objects like the crab nebula.

Answer:

D. visible light