Ionisation Energy

AQA:

• define first ionisation energy 

• write equations for first and successive ionisation energies 

• explain how first and successive ionisation energies in Period 3 (Na–Ar) and in Group 2 (Be–Ba) give evidence for electron configuration in sub-shells and in shells. 

Edexcel: 

• be able to define the terms ‘first ionisation energy’ and ‘successive ionisation energies’ 

• understand how ionisation energies are influenced by the number of protons, the electron shielding and the electron sub-shell from which the electron is removed 

• understand reasons for the general increase in first ionisation energy across a period 

• understand reasons for the decrease in first ionisation energy down a group  

OCR:

• first ionisation energy (removal of 1 mol of electrons from 1 mol of gaseous atoms) and successive ionisation energy

• explanation of the trend in first ionisation energies across Periods 2 and 3, and down a group, in terms of attraction, nuclear charge and atomic radius

• prediction from successive ionisation energies of the number of electrons in each shell of an atom and the group of an element