Among the statements (I - IV), the correct ones are:
(I) Be has smaller atomic radius compared to Mg.
(II) Be has higher ionization enthalpy than AI.
(III) Charge/radius ratio of Be is greater than that of AI.
(IV) Both Be and AI form mainly covalent compounds.
(I) Be has smaller atomic radius compared to Mg.
(II) Be has higher ionization enthalpy than AI.
(III) Charge/radius ratio of Be is greater than that of AI.
(IV) Both Be and AI form mainly covalent compounds.
- (A)(I), (III) and (IV)
- (B)(II), (III) and (IV)
- (C)(I), (II) and (III)
- (D)(I), (II) and (IV)✓ Correct
Answer: (D)
Solution
Statement (I) holds: moving down group 2, Be sits above Mg and so has the smaller atom. Statement (II) holds: Be, being small with a high effective nuclear charge, has a higher ionisation enthalpy than Al. Statement (III) fails: the diagonal relationship between Be and Al rests on their charge-to-radius ratios being comparable, not on Be exceeding Al. Statement (IV) holds: both, with their high charge density and strong polarising power, form mainly covalent compounds. The correct set is (I), (II) and (IV).
JEE Main · 2020 · 03 Sep 2020 · Shift 2 · Single correct option