Ionisation energies AS Chemistry

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Ionisation energies

if an atom loses an electron it forms a positive ion 

the first ionisation energy is the amount of energy needed to remove one mole of electrons form one mole of gaseous atoms

equations of first ionisation energy can be written like this

Na(g)= Na+(g)+e- 

however an ion can have more electrons removed and form an ion with a 2 plus charge

Na+(g)+= Na+2(g)+ e-

an atom can have as many ionisations energies as the number of electrons they have but the electrons get increasingly harder to remove reasons for this are