Question

Assertion : In the series $Sc$ to $Zn$, the enthalpy of atomisation of zinc is the lowest.
Reason : Zinc has greater number of unpaired electrons.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (C)

Zinc does not have unpaired electrons in ground state as well as in its common oxidation state. Enthalpy of atomisation depends upon the number of unpaired electrons. Greater the number of unpaired electrons, stronger is the interatomic metallic bonding and higher is the enthalpy of atomisation.