Evaluate the following statements related to group 14 elements for their correctness. Choose the correct answer from the options given below :
- (A), (B) and (C) Only
- (A) and (B) Only
- (C), (D) and (E) Only
- (C) and (D) Only
Answer
(3) (C), (D) and (E) Only
Solution
(A): extra shells are added ⇒ covalent radius increases from C to Pb ⇒ (A) is wrong
(B): EN falls from C (2.5) to Si (1.8), then stays nearly constant (Ge, Sn 1.8; Pb 1.9) ⇒ not gradual ⇒ (B) is wrong
(C): C has no d orbitals (n = 2) ⇒ covalency 4; Si onwards use d orbitals ⇒ (C) is correct
(D): large atoms give poor sideways p–p overlap ⇒ no p - p bonds ⇒ (D) is correct
(E): C is more electronegative than H, e.g. CH4 (−4) ⇒ (E) is correct
∴ (C), (D) and (E) only
Answer: (3)