What drives the anomalous ground-state electronic configuration of Chromium () compared to its expec — d and f Block Elements Chemistry Question

💡 Solution & Explanation

The energy gap between $3d$ and $4s$ is very small. Shifting one electron from $4s$ to $3d$ yields a exactly half-filled $d^5$ subshell, which is highly stable due to symmetrical charge distribution and maximum exchange energy.