The electronic structure of zinc (Z = 30) is 2, 8, 18, 2. The electronic structure of gallium (Z = 3 — Atomic Structure Chemistry Question

💡 Solution & Explanation

Zinc (Z = 30) has the ground-state electronic configuration [Ar] 3d^10 4s^2, which corresponds to shell-wise populations: n=1 (2), n=2 (8), n=3 (18), n=4 (2). Gallium (Z = 31) has one additional electron, which enters the 4p subshell because the 4s and 3d levels are completely filled. This gives the configuration [Ar] 3d^10 4s^2 4p^1. Grouping by principal quantum shells: n=1 (2), n=2 (8), n=3 (18), n=4 (3). Thus, the electronic structure is 2, 8, 18, 3.