Question

Why does the speed of light change in different mediums?

Answer 1

Because the densities of different mediums are different and for the same it decreases or increases

. Rarer means more speed and denser medium low speed .

Answer 2

The speed of light changes in the different medium due to the changing of density of different mediums. If the density increases then the speed decreases and if the density decreases then the speed increases. So, the speed of light and the density of of the medium are inversely proportional to each other. During the time of refraction if the density of the refractive medium increases then the light ray bends towards the normal and if the density of the refractive medium decreases then the light ray bends away from the normal.