Question

In the series $Sc(Z=21)$ to $Zn(Z=30)$, the enthalpy of atomisation of which element is least?

• A. Sc
• B. Mn
• C. Cu
• D. Zn

Answer 1

Answer: (D)

Zn

$Sc\&Zn$ belongs to the third group of the periodic table. The extent of metallic bonding an element undergoes decides the enthalpy of atomization. The more extensive the metallic bonding of an element, the more will be its enthalpy of atomization. In all transition metals, there are some unpaired electrons that account for their stronger metallic bonding.

Due to the absence of these unpaired electrons, the inter-atomic electronic bonding is the weakest in $Zn$ and as a result, it has the least enthalpy of atomization.