8.4- A CLOSER LOOK AT IONISATION ENERGIES

Question 1

How does first ionisation energy between Group 2 and 3 change?

Answer 1

first IE drops

Question 2

How does first IE between Group 5 + 6 change?

Answer 2

drops

Question 3

Why is there a drop in first ionisation energy between Group 2 and 3?
magnesium - 1s2 2s2 2p6 3s2
aluminium 1s2 2s2 2p6 3s2 3p1

Answer 3

magnesium loses a 3s electron
aluminium loses a 3p electron

p-electron already in higher energy level than s-electron, so takes less energy to remove it

Question 4

Why is an electron in a pair easier to remove than one in an orbital on its own?

Answer 4

as it’s already being repelled by the other electron

Question 5

Why is there a drop in first IE between Group 5 + 6?
phosphorus 1s2 2s2 2p6 3s2 3p3
sulfur 1s2 2s2 2p6 3s2 3p4

Answer 5

phosphorus has no paired electrons in p-orbital so each p-electron is in different orbital
sulfur has two of its p-electrons paired in p-orbital so one of these will be easier to remove than unpaired one due to repulsion of other electron in same orbital

Question 6

If you remove the electrons from an atom one at a time, how does something change?

Answer 6

each one is harder to remove than the one before