3.1.4 Evidence for electron shells

3.1.4 Evidence for electron shells

1. First Ionisation Energy: energy required to remove 1 electron from each atom of 1 mole of gaseous to form 1 mole of gaseous 1+ ions

2. How does electron shielding affect first ionisation energy?

   • increases down a group
   • reduces the attraction of the nucleus down a group

3. How does atomic radius affect first ionisation energy?

   • increases down a group
     • decreases across a period

4. How does nuclear charge affect first ionisation energy?

   • increases down a group
   • more protons and charged nucleus
   • electrons are more strongly attracted

5. Successive Ionisation Energy: measure of amount of energy required to remove each electron in turn