L6 - Electron Arrangements + Ionisation

Question 1

What is the first ionisation energy?

Answer 1

the energy required to remove one mole of electrons (to infinity) from one mole of gaseous atoms to form one mole of gaseous positive ions

Question 2

ionisation energies

what pattern do you see across a period?

Answer 2

They generally increase across a period cause the nuclear charge is increasing + this makes it more difficult to remove an electron

each time an electron goes into a new sub-level there is a small dip

Question 3

ionisation energies

what pattern do you see down a group?

Answer 3

the nuclear charge increases

which makes it easier to remove an electron

because the positive charge ‘felt’ by an electron in the outer shell is less than the full nuclear charge

because the inner electrons shield the nuclear charge

Question 4

What are successive ionisation energies?

Answer 4

the energy required to remove electrons from positively charge ions

(species that already had electrons removed)

Question 5

what pattern do you see with successive ionisation energies?

Answer 5

They always increase in energy
cause the electrons are being removed from more positive species,
which requires more energy

We see big jumps in successive ionisation energy when there is a change of shell.
This is because there is a big decrease in the amount of shielding.