Which describes how electromagnetic waves travel

a. they can only travel through a medium.

b. they can travel through a vacuum but not through matter.

c. they can travel through matter and through a vacuum.

d. they can only travel through matter.

c. They can travel through matter and through a vacuum.

Explanation: Electromagnetic waves are waves which do not require medium to travel. Example: Light

Mechanical waves are waves which require material medium to travel through them.  Mechanical waves require the presence of a material medium in order to transport their energy from one location to another. Example: Sound

Mechanical waves  can only travel through a medium and they can only travel through matter.

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation:

where is the photo and the answer choices?