Factors affecting ionisation energy

Factors affecting ionisation energy

1. Nuclear charge

   • More protons there are in a nucleus
     • More positively charged the nucleus
       • Stronger the attraction for the electrons

2. Distance from nucleus

   • Attraction falls off rapidly with distance
     • Electron closer to nucleus is more strongly attracted
       • Than one further away

3. Shielding

   • As number of electrons between outer electrons and nucleus increases
     • Outer electrons feel less attraction towards nuclear charge
       • This lessening of pull of the nucleus by inner shells of electrons is
         • Shielding (or screening)