Transition elements extensively form stable, non-stoichiometric interstitial compounds with lightwei — d and f Block Elements Chemistry Question

💡 Solution & Explanation

Interstitial compounds trap small atoms ($H, C, N$) in the metallic lattice without forming proper covalent bonds, so the delocalized electron "sea" remains undisturbed, retaining metallic conductivity. Physically, the trapped atoms severely restrict the sliding of crystal planes, making the compounds incredibly hard, raising their melting points above the pure metal, and rendering them highly chemically inert.