Brian L. answered 11/15/23
Pharmacist Specializing In Many Areas of Math and Science
When an electron goes from a higher energy orbital (higher n), to a lower energy orbital (lower n), it will emit a photon of energy equal to the difference in energy values between the two orbitals. My interpretation of the table is that the energy of the photon emitted when an electron moves from n = 3 orbital to n = 2 orbital is the difference between -1.51 eV and -3.40 eV; that is 1.89 eV.