Question

multiple choice 1 point
why do electromagnetic waves slow down in mediums like water and glass?
due to the high density of the medium
because they do not need a medium to travel
because they need a medium to travel
due to the low density of the medium

Explanation:

Electromagnetic waves slow down in media like water and glass because the atoms and molecules in these media interact with the waves. The higher - density media have more particles for the waves to interact with, causing the waves to slow down. The fact that electromagnetic waves don't need a medium to travel (which is true in vacuum) is not the reason for their slowing in these media. Low - density media would not cause the waves to slow down.

Answer:

Due to the high density of the medium