Concept:Bond energy is strongly dependent on bond length. Shorter bonds are generally stronger. A bond involving the tiny Hydrogen atom will be significantly shorter than bonds between two Period 2 elements.
Formula:$$ \text{Bond Energy} \propto \frac{1}{\text{Bond Length}} $$
Solution:- Hydrogen is the smallest atom (only a 1s orbital). Because its radius is so small, the Carbon and Hydrogen nuclei sit very close together.
- This short distance (approx. 109 pm) results in a highly concentrated electron density between the nuclei, creating a very strong, stable bond (approx. 413 kJ/mol).
- Bonds like C-C, C-N, and C-O involve two larger atoms (Period 2), resulting in longer, slightly weaker single bonds (ranging from 300 to 350 kJ/mol).
Why other options are incorrect:- Option B, Option C, Option D: All feature longer internuclear distances compared to a C-H bond, resulting in lower bond dissociation energies.
Quality & Fidelity Assurance:
Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.