Ionisation Energies

Ionisation Energies

1. The energy needed to remove 1 mole of electrons from one mole of gaseous atoms to form one mole of positive gaseous ions.

2. Factors affecting ionisation energy

   • Nuclear Charge
   • Distance from Nucleus
   • Electron Shielding

3. Trends

   • Decrease down a group
   • Generally increase across a period

4. Successive Ionisation Energies

   • Within each shell they increase
   • Big jump when new shell is broken into