Chemistry - PERIODIC TABLE Question with Solution | TestHub
B has a smaller first ionization enthalpy than Be. Consider the following statements and calculate the number of correct 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
Answer:
Solution:
The first ionization enthalpy of B (1s²2s²2p¹) is lower than Be (1s²2s²).
(I) Correct: Removing a 2p electron from B is easier than a 2s electron from Be due to the higher energy and poorer penetration of 2p orbitals.
(II) Correct: The 2p electron in B experiences greater shielding from the 1s² and 2s² electrons compared to the 2s electron in Be, which is only shielded by 1s².
(III) Correct: 2s electrons have greater penetration power than 2p electrons, meaning they spend more time closer to the nucleus and are more strongly attracted.
(IV) Incorrect: Atomic radius generally decreases across a period. B has a smaller atomic radius than Be due to increased nuclear charge.
Number of correct statements = 3.
