Sigma & Pi Bonds

Head-on and side by side

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• σ: head-on overlap (every single bond); π: side-by-side p overlap.
• Double = σ + π, triple = σ + 2π.
• π bonds stop rotation: the reason cis/trans isomers exist.

Steps

1. Two ways to overlap
2. Count σ in ethene
3. Count π in HCN
4. Twist a double bond
5. Free to spin?
6. Vinegar’s σ bonds