The Bohr model of the hydrogen atom states that the single electron can exist only in certain allowed orbits around the proton. The radius of each Bohr orbit is r = n2(0.052 9 nm) where n = 1, 2, 3, . . . . Calculate the electric potential energy of a hydrogen atom when the electron
(a) Is in the first allowed orbit, with n = 1,
(b) Is in the second allowed orbit, n = 2, and
(c) Has escaped from the atom, with r = *. Express your answers in electron volts.