Breaking the Octet Rule

Too few, too many, and odd numbers

An interactive lesson with 7 steps, about 6 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Boron often has only six electrons (BF₃) and accepts a lone pair readily.
• Odd electron counts mean radicals (NO, NO₂).
• Period-3 atoms and below can bond to 5 or 6 neighbours (PCl₅, SF₆).

Steps

1. Rules of thumb
2. Boron trifluoride
3. An empty seat
4. Sulfur hexafluoride
5. A crowded atom
6. Spot the radical
7. Five neighbours