The number of unpaired electron in G. S., first E. S. and second E. S. of S (Z = 16) are, respective — Atomic Structure Chemistry Question

💡 Solution & Explanation

Sulfur (Z = 16) has the ground-state (G. S.) electronic configuration: [Ne] 3s^2 3p^4. In the 3p subshell (which has 3 degenerate orbitals), there are 2 unpaired electrons. Ground State (G. S.): [Ne] 3s^2 3p^4 3d^0 => 2 unpaired electrons. First Excited State (1st E. S.): One electron from the paired 3p orbital is excited to the vacant 3d subshell, yielding the configuration [Ne] 3s^2 3p^3 3d^1 => 4 unpaired electrons (3 in 3p and 1 in 3d). Second Excited State (2nd E. S.): An electron from the filled 3s orbital is further excited to the 3d subshell, yielding the configuration [Ne] 3s^1 3p^3 3d^2 => 6 unpaired electrons (1 in 3s, 3 in 3p, and 2 in 3d). Thus, the number of unpaired electrons is 2, 4, and 6, respectively.