Molecular orbital theory: homonuclear diatomics up to Ne2
Advanced Chemical Bonding · Chemistry
Study notes
Predict bond order and magnetism for C₂ and N₂. Step 1: C₂ (8 valence e⁻): (σ2s)²(σ*2s)²(π2p)⁴. BO = ½(6-2) = 2. Step 2: Two unpaired π electrons → paramagnetic (observed!). Step 3: N₂ (10 e⁻): (σ2s)²(σ*2s)²(π2p)⁴(σ2p)². BO = ½(8-2) = 3. Step 4: All paired → diamagnetic; triple bond explains N₂'s inertness.