Light rays travel from one medium into another and refract away from the boundary. What changes about the light to cause this refraction? A. Its speed increases.
B. Its frequency increases.
C. Its frequency decreases.
D. Its speed decreases.

An electron moved from a lower energy level to a higher energy level. what most likely happened during the transition? a random amount of light was released. a fixed amount of energy was absorbed. a fixed amount of energy was released. a random amount of light was absorbed.