Which describes the refraction of a wave? a. waves of electromagnetic energy called x-rays pass right through skin and bones. b. light changes direction moving through the lens of a magnifying glass. c. a wave of sound bounces off a hard surface at the same angle that the wave came in.

Materials will have different energies associated with the electrons inside them. this is related to how strongly bound they are by their work function. if we sandwich a material with a very low energy between two materials with a high energy, we create a trap for an electron. if this trap is very narrow in one direction in comparison to the others, this is approximately a 1-dimensional box that confines the electron. what is the lowest energy of an electron in the box if the thinnest direction across the materials is 4.81 nm?