If a helium atom absorbs a photon with a wavelength of 58.44 nm, one electron will be promoted from the 1s orbital to a 2p orbital. Find the energy, in J, gained by a helium atom undergoing this transition.
The ionization energy of helium is 2372 kJ/mol. Suppose that a helium atom has already undergone the transition above, so that it has one electron in a 2p level. What is the longest wavelength of light that would be capable of supplying enough energy to eject an electron from this excited helium atom, producing a He+ ion?