Question

The energies of the same orbital decreases with an increase in the atomic number. Justify this statement.

Answer 1

The energy of the 2s orbital of hydrogen atom is greater than that of 2s orbital of lithium and that of lithium is greater than that of sodium and so on because H (Z =1), Li (Z = 3) and Na (Z = 11). When atomic number increases, the energies of the same orbital decreases. E_2s(H) > E_2s(Li) > E_2s(Na) > E_2s(K) ……