What is the index of refraction?

Responses

the ratio of the speed of light in a vacuum to the speed of light in the material it is passing though

the ratio of the speed of light in a vacuum to the speed of light in the material it is passing though

the difference between the angle at which the light ray enters the new medium and the angle at which it is reflected

the difference between the angle at which the light ray enters the new medium and the angle at which it is reflected

the amount the light ray has bent toward the normal line when entering a new medium

the amount the light ray has bent toward the normal line when entering a new medium

the percentage that the light ray bent when it entered the new medium

the ratio of the speed of light in a vacuum to the speed of light in the material it is passing though