Evaluate the following statements related to group 14 elements for their correctness.
(A) Covalent radius decreases down the group from C to Pb in a regular manner.
(B) Electronegativity decreases from C to Pb down the group gradually.
(C) Maximum covalance of C is 4 whereas other elements can expand their covalance due to presence of d orbitals.
(D) Heavier elements do not form p π-p π bonds.
(E) Carbon can exhibit negative oxidation states.
Choose the correct answer from the options given below :

Solution

Chemistry ma’am · 3 steps

Test each claim against the real data: radius goes up, and electronegativity barely moves after silicon.

1. Trend statements. (A) and (B) describe smooth trends down the group. Check them against the actual values before you accept them. The table uses the textbook values.

   Statement	What the data or chemistry says	Verdict
   (A) Covalent radius decreases	C 77, Si 118, Ge 122, Sn 140, Pb 146 pm. It increases down the group, and not by equal amounts.	False
   (B) Electronegativity falls gradually	C 2.5, then Si, Ge and Sn are all 1.8, and Pb is 1.9. There is one big drop, then almost no change.	False
   (C) C limited to covalency 4	C has only 2s and 2p orbitals. Si onwards use d orbitals, as in [SiF₆]²⁻.	True
   (D) No pπ - pπ bonds for heavier elements	Large atoms give poor sideways overlap of p orbitals. Only C forms stable C=C and C≡C bonds.	True
   (E) Negative oxidation states for C	C is more electronegative than H and metals. It shows -4 in CH₄ and in carbides such as Al₄C₃.	True

2. Why C is different. Carbon is small, highly electronegative and has no d orbitals. That one fact explains why (C), (D) and (E) are all true.
3. So. (A) and (B) are false, and (C), (D) and (E) are correct, which is option (c).

The idea to keep. Down group 14, radius increases with a big jump from C to Si. Electronegativity drops sharply from C to Si and then stays almost flat. Carbon's small size and lack of d orbitals make it the odd one out.

Answer from the NTA final answer key. Solution by PrepWiser.