Consider the following statements:
(A) NF₃ molecule has a trigonal planar structure.
(B) Bond length of N₂ is shorter than O₂.
(C) Isoelectronic molecules or ions have identical bond order.
(D) Dipole moment of H₂S is higher than that of water molecule.
Choose the correct answer from the options given below:

Solution

Chemistry ma’am · 3 steps

Check each statement against one fact you know: shape, bond order, electron count, electronegativity.

1. Shape and polarity. N in NF₃ has three bond pairs and one lone pair, so the shape is trigonal pyramidal, not planar. In H₂S the S–H bonds are much less polar than O–H, because S is far less electronegative than O.
2. Bond order. A higher bond order means a shorter bond. Isoelectronic diatomic species fill the same molecular orbitals with the same number of electrons, so they get the same bond order, for example N₂, CO, CN⁻ and NO⁺ all have bond order 3.

   Statement	Check	Verdict
   (A) NF₃ trigonal planar	3 bond pairs + 1 lone pair, so pyramidal	False
   (B) N₂ shorter than O₂	Bond order 3 (about 110 pm) vs 2 (about 121 pm)	True
   (C) Isoelectronic species, same bond order	Same electron count, same MO filling, e.g. N₂ and CO both 3	True
   (D) H₂S more polar than H₂O	H₂O is about 1.85 D, H₂S only about 0.97 D	False

3. So. Only (B) and (C) are correct, which is option (c).

The idea to keep. Count lone pairs on the central atom before naming a shape. And remember: more bonds between two atoms pull them closer, so higher bond order means shorter bond.

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