Question

B has a smaller first ionization enthalpy than Be. Consider the following statements:
(I) it is easier to remove $2p$ electron than $2s$ electron
(II) $2p$ electron of B is more shielded from the nucleus by the inner core of electrons than the 2s electrons of Be
(III) $2s$ electron has more penetration power than $2p$ electron
(IV) atomic radius of B is more than Be(atomic number B = 5, Be = 4)
The correct statements are :

• A. (I), (II) and (III)
• B. (II), (III) and (IV)
• C. (I), (III) and (IV)
• D. (I), (II) and (IV)

Answer 1

Answer: (A)

$Be\Rightarrow 1s^{2}2s^2$
$B\Rightarrow 1s^{2}2s^{2}2p_1$
B has a smaller size than Be
it is easier to remove 2p electron than 2s electron due to less pentration effect of 2p than 2s.
2p electron of Boron is more shielded from the nucleus by the inner core of electron than the 2s electron of Be
B has a smaller size than Be