ionisation energies

Question 1

Ionisation energies across the period

Answer 1

INCREASES:
- nuclear charge increases

• no change in shielding or nuclear distance
• more energy required to increased attraction between valence e- and nucleus

Question 2

ionisation energies across a period - exceptions

Answer 2

groups 2&3 in periods 2&3: Be/ B and Mg/ Al

groups 5&6 in periods 2&3:
N/O and P/ S

Question 3

Why are there exceptions in Group 2&3?

Answer 3

• shielding means easier to remove electron in the 2p/ 3p sub-shell
• higher in energy level
• so further away from the nucleus so there is less attraction

Question 4

why are there exceptions in groups 5&6

Answer 4

• O and S have paired electrons in their 2p/3p sub-shells
• repulsive forces make it easier to remove since it’s less stable

Question 5

succesive ionisation energies

Answer 5

Group 1: big jump between 1&2
Group 2: big jump between 2&3

etc etc