Evaluate the observed electronic configurations of Chromium () and Copper (). Which theoretical fact — d and f Block Elements Chemistry Question

💡 Solution & Explanation

Very little energy difference exists between the $3d$ and $4s$ orbitals. An electron shifts $s \rightarrow d$ to maximize exchange energy and achieve a symmetrical, highly stable $d^5$ (Chromium) or $d^{10}$ (Copper) configuration.