Glass
Water
Air
Vacuum
Answer is Wrong!
Answer is Right!
The correct answer is: D. Vacuum.
Light travels fastest in a vacuum, followed by air, water, and glass.
The speed of light in a vacuum is 299,792,458 meters per second. The speed of light in air is about 299,702,547 meters per second. The speed of light in water is about 225,000,000 meters per
second. The speed of light in glass is about 200,000,000 meters per second.The speed of light in a medium is slower than the speed of light in a vacuum because the light waves interact
with the atoms and molecules in the medium. The more dense the medium, the slower the speed of light.A vacuum is a space that is completely empty of matter. There are no atoms or molecules in a vacuum, so light waves do not interact with anything and can travel at their fastest speed.