The refractive index of diamond is 2.42. What is the critical angle for the light passing from the diamond to the air?

The critical angle is the angle of incidence at which the light is refracted at an angle of 90 degrees. The critical angle can be calculated using Snell's Law: sin(critical angle) = 1 / refractive index. For diamond (n=2.42) to air (n=1), the critical angle is approximately 24.4 degrees.