Assertion (A): Boron has a smaller first ioni | vedclass

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(C) Assertion $(A)$: Electronic configuration of Boron $(Z=5)$ is $[He] 2s^2 2p^1$. In the first ionisation ($IE_1$ or $\Delta_i H_1$),the electron is

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Assertion and Reason both are correct statements and Reason is correct explanation for Assertion.

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(C) Assertion $(A)$: Electronic configuration of Boron $(Z=5)$ is $[He] 2s^2 2p^1$. In the first ionisation ($IE_1$ or $\Delta_i H_1$),the electron is removed from the $2p^1$ orbital.Electronic configuration of Beryllium $(Z=4)$ is $[He] 2s^2$. The electron is removed from the fully filled $2s^2$ orbital,which is more stable and requires more energy.Thus,the Assertion is correct.Reason $(R)$: The $s$-orbital is spherical and closer to the nucleus,providing better shielding for the $2p$ electron from the nuclear charge. Consequently,the $2p$ electron in Boron experiences a lower effective nuclear charge compared to the $2s$ electrons in Beryllium,making it easier to remove.Therefore,the Reason is the correct explanation for the Assertion.

Assertion $(A)$: Boron has a smaller first ionisation enthalpy than beryllium.
Reason $(R)$: The penetration of a $2s$-electron to the nucleus is more than the $2p$-electron; hence,the $2p$-electron is more shielded by the inner core of electrons than $2s$-electrons.

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Assertion $(A)$: Boron has a smaller first ionisation enthalpy than beryllium.Reason $(R)$: The penetration of a $2s$-electron to the nucleus is more than the $2p$-electron; hence,the $2p$-electron is more shielded by the inner core of electrons than $2s$-electrons.