JEE Main · 2019 · 09 Jan 2019 · Shift 2 · d and f Block Elements

Enthalpy of atomisation measures how strongly the metal atoms are bonded in the solid, which depends on unpaired $d$ electrons being available for metallic bonding. Zinc has a filled $3d^{10}4s^2$ shell with no unpaired $d$ electrons, so its metallic bonding is weak and its enthalpy of atomisation is the lowest of $\mathrm{Fe}$, $\mathrm{Cu}$, $\mathrm{V}$ and $\mathrm{Zn}$.