Question

The refractive index of diamond is 2.42 what is the meaning of this statement please answer it very fast it's important

Answer 1

it means that the diamond's cubical structure is more denser and the light when passes through diamond,the light collide with its inner walls of it before coming out of the diamond.

Answer 2

n=c upon v v=c upon n
=1upon 2.42 multiply c
then speed of light is 1 upon2.42 times the speed of light in vaccum