GS A 1-cm-thick layer of water stands on a horizontal slab
of glass. A light ray in the air is incident on the water
65° from the normal.

Can anybody me with this? ? (picture included.)

This is the substance(s) formed in a chemical reaction.

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.