Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE

The ground state electronic configuration of the central nitrogen atom in \( \text{NH}_3 \) is \( 2s^2 2p_x^1 2p_y^1 2p_z^1 \). The observed \( \text{H}-\text{N}-\text{H} \) bond angle is reduced from \( 109.5^\circ \) to \( 107^\circ \) primarily because:

1. Bond pair-bond pair repulsion is stronger than lone pair-bond pair repulsion
2. Lone pair-bond pair repulsion is greater than bond pair-bond pair repulsion
3. Nitrogen undergoes \( sp^2 \) hybridisation instead of \( sp^3 \)
4. Hydrogen atoms attract each other