Ionisation Energies

Question 1

Ionisation energies

Answer 1

It is the energy needed to remove electrons from each atom to form a certain amount of moles of gaseous charged ions

Question 2

Three factors that affect ionisation energy

Answer 2

1) nuclear charge
The more protons there are in the nucleus the more positively charged the nucleus is and the stronger the attraction for the electrons

2) electron shell
An electron in the shell close to the nucleus will be more strongly attracted to one further away

3) shielding
The more shielding there is, the less the pull on the nucleus by inner shells of electrons

Question 3

First ionisation energies decrease down a group

Answer 3

As you go down the group

each element has extra electron shells therefore the atomic radius is larger so outer electrons are further away from the nucleus

Question 4

Ionisation energy increases across a period

Answer 4

As you move across a period the ionisation Energy increases because the number of protons is increasing which means stronger nuclear attraction

The extra electrons are at roughly the same energy level this means there is generally little or extra shielding effect or extra distance to lessen the attraction from the nucleus