Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE

What is the primary factor that makes a \( \sigma \) bond stronger than a \( \pi \) bond formed between the same two atoms?

1. Axial head-on overlap permits a larger extent of orbital overlapping along the internuclear axis
2. Sidewise overlap provides greater electron density above and below the internuclear axis
3. A \( \sigma \) bond involves only pure \( s \)-orbitals whereas a \( \pi \) bond involves \( d \)-orbitals
4. A \( \pi \) bond is formed before the \( \sigma \) bond and repels approaching nuclei