Question

unit 7 \physical interaction\ test
light travels fastest in ______.
○ solids.
○ empty space.
○ seawater
○ fresh water

Explanation:

Light travels fastest in a vacuum (empty space) as there are no particles to interact with and slow it down. In solids, liquids like seawater and fresh - water, light interacts with atoms and molecules which causes it to slow down.

Answer:

B. empty space