Ionisation Energy

How tightly electrons are held

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

• Ionisation energy rises across a row and peaks at the noble gases.
• Alkali metals have low ionisation energies: one electron in a new shell.
• Electron transfer between sodium and chlorine creates the ions of salt.

Steps

1. Pulling off an electron
2. Atomic sizes
3. Successive ionisations
4. Salt
5. Helium’s lone electron
6. A small dip