explain step by step how

13. [5marks] A sample of a one-electron ion initially in the ground state was selectively excited to an excited state with n = 9. As the excited state ions relaxed to the ground state by undergoing transitions to lower energy states, photons were emitted from the sample. The lowest energy photons were selectively reflected onto a metal foil. When the metal foil was lithium, electrons were ejected. No electrons were ejected when a calcium foil was used. (The binding energy of Li is 2.4 eV the binding energy of Ca is 2.9 eV). (a) Which transition(s) correspond to the lowest energy photons emitted from the one-electron ion (e.g., 41)? 9-8 (b) Identify and give the charge of the one-electron ion present in the sample. 2.4 eV