Official Correct Choice:
Option B: \( \text{CH}_4, \text{NH}_4^+, \text{MnO}_4^-, \text{NF}_3 \)
Concept:Molecules with \( \text{sp}^3 \) or higher hybridization (in 3 dimensions) are generally non-planar, while those with purely \( \text{sp}^2 \) or \( \text{sp} \) hybridization lacking lone pair distortions tend to be planar or linear.
Formula:$$ \text{sp}^3 \text{ hybridization} \implies \text{Tetrahedral / Pyramidal (3D/Non-planar)} $$
Solution:- \( \text{CH}_4 \), \( \text{NH}_4^+ \), and \( \text{MnO}_4^- \) have perfect tetrahedral geometries (non-planar).
- \( \text{NF}_3 \) has a trigonal pyramidal geometry (non-planar).
- Thus, every species in this option extends into three dimensions and is strictly non-planar.
Why other options are incorrect:- Option A: \( \text{C}_2\text{H}_4 \), \( \text{BF}_3 \), and \( \text{NO}_3^- \) are all strictly planar.
- Option C: Ethene (\( \text{CH}_2=\text{CH}_2 \)) is planar, and \( \text{BeCl}_2 \) is linear (1D).
- Option D: \( \text{SO}_3 \) and Benzene are entirely planar molecules.
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