consider-the-following-illustration-of-the-periodic-table-identify-which-among-t

Question

Consider the following illustration of the periodic table. Identify which among the highlighted elements has an anomalous ground-state electron configuration. Justify your answer.

Accepted Answer

B; The expected electron configuration of Ag is [Kr]$$5s^{2}4d$$^{9}$$ but the d orbitals prefer to have fully-filled orbitals so the actual electron configuration is [Kr]5s$$^{1}$$4d^{10}.$$

Answer

A; The expected electron configuration of Cl is [Ne]$$3s^{2}3p$$^{5}$$ but the p orbitals prefer to have fully-filled orbitals so the actual electron configuration is [Ne]3s$$^{1}$$3p^{6}.$$

Answer

C; The expected electron configuration of Cs is [Xe]$$6s^{1}$$ but the s orbitals prefer to have half-filled orbitals so the actual electron configuration is [Xe]$$6s^{2}.$$