What did Heraclitus mean when he said, “You never see the same river twice”? A. Individual perception is always changing.
B. Water is in all solids found in the universe.
C. Once something is seen, it cannot be unseen.
D. A river will change from one time you see it to the next.

An electron is trapped at a defect in a crystal. the defect may be modeled as a one-dimensional, rigid-walled box of width 1.00 nm. (a) sketch the wavefunctions and probability densities for the n 1 and n 2 states. (b) for the n 1 state, nd the probability of nding the electron between x1 0.15 nm and x2 0.35 nm, where x 0 is the left side of the box. (c) repeat (b) for the n 2 state. (d) calculate the energies in electron volts of the n 1 and n 2 states