Chemistry · Classification of Elements and Periodicity in Properties
हिन्दीGiven below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Boron has a smaller first ionization enthalpy than beryllium. Reason (R): The penetration of a \( 2s \)-electron to the nucleus is more than that of a \( 2p \)-electron, making the \( 2p \)-electron of boron more shielded from the inner core than the \( 2s \)-electron of beryllium. In the light of the above statements, choose the correct answer from the options given below:
Correct answer · Option 1
Both (A) and (R) are true and (R) is the correct explanation of (A).
Explanation
Due to greater penetration of 2s electrons compared to 2p electrons, removing a 2p electron from boron requires less energy than removing a 2s electron from beryllium.