What best describes why the critical angle of an air-glass boundary is 39.3°? A. It is the angle of refraction in glass for which the angle of incidence in air is 90°. B. It is the angle of incidence in air for which the angle of refraction in glass is 90°. C. It is the angle of refraction in air for which the angle of incidence in glass is 90°. D. It is the angle of incidence in glass for which the angle of refraction in air is 90°.

It is the angle of refraction in glass for which the angle of incidence in air is 90°.

Explanation:

When light is refracted, the sine of the angle changes in proportion to the refractive index. When the light is 90 degrees, the sine is zero, and zero is still zero on the other side. So nothing changes.

i don't understand is there any other way you can rephrase it plz let me know in the comments and i will do it.

explanation:

the answer is false. this is because for ice to melt, it requires latent heat of melting. latent heat means heat energy required to change phase without any increase in temperatures. therefore, the ice will take energy from the environment to melt hence atmospheric temperatures will reduce.