(a) Consider the following three statements: 

(i) A hydrogen atom in the n = 3 state can emit light at only two specific wavelengths, 

(ii) A hydrogen atom in the n = 2 state is at a lower energy than the n = 1 state, 

(iii) The energy of an emitted photon equals the energy difference of the two states involved in the emission. Which of these statements is or are true?

(b) Does a hydrogen atom “expand” or “contract” as it moves from its ground state to an excited state?