Question

Assertion :1st ionization energy of $P$ is greater than $S$. Reason: $Z_{eff}$ value of $S$ is greater than $P$.

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 B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.

The first ionization energy of $P:\left[Ne\right]3s^{2}3p^3$ is greater than $S:\left[Ne\right]3s^{2}3p^4$ because $P$ has half-filled electronic configuration and it is difficult to remove an electron from stable species.

$Z_{e}ff$ value of $S$ is 2.5 and that of $P$ is 2.1 .

Hence, the correct option is $B$