Ionisation energy (not incl. the graphs)

Question 1

Define first ionisation energy

Answer 1

Energy required to remove one electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions

Question 2

What happens to nuclear charge across the period?

Answer 2

Increases due to there being more protons

Question 3

What happens to atomic radius when nuclear charge increases?

Answer 3

Electrons pulled closer to nucleus, decreasing atomic radius

Question 4

What happens to first ionisation energy as atomic radius decreases?

Answer 4

Increases

Question 5

What does a high ionisation energy mean?

Answer 5

High attraction between electrons and nucleus so more energy needed to remove electron

Question 6

Why does ionisation energy decrease down a group?

Answer 6

Atomic radius increases and greater shielding from inner shells

Question 7

Why does group 6 have a lower ionisation energy then group 5 (in the same period)

Answer 7

Group 6 - electron removed from orbital with two electrons, so there’s repulsion (easier to move)

Question 8

Why does group 3 have a lower ionisation energy than group 2 (in the same period)?

Answer 8

Group 3 - outermost electron in p-orbital which has high energy so electron is further from nucleus

Group 2 - outermost electron in s-orbital (lower energy level)