Question

Assertion :Electron affinity of $F$ is less than $Cl$. Reason: Additional electrons are repelled more effectively by $3p$-electrons in $Cl$-atom than by $2p$-electrons in $F$-atom.

Read the above assertion and reason and choose the correct option regarding it.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
• C. Assertion is correct but Reason is incorrect.
• D. Assertion is incorrect but Reason is correct.

Answer 1

The correct option is C Assertion is correct but Reason is incorrect.

Option (C) is correct. Additional electrons are repelled less effectively by $3p$-electrons in $Cl$-atom than by $2p$-electrons in $F$-atom.Fluorine's electron affinity is smaller than chlorine's because of the higher electron - electron repulsions in the smaller $2p$ orbital compared to the larger $3p$ orbital of chlorine.