7.2 Ionisation Energies

Question 1

Trend in 1st ionisation energy down a group

Answer 1

• atomic radius increases
• more inner shells so shielding increases
• nuclear attraction on outer electrons decreases
• 1st ionisation energy decreases

Question 2

Trend in 1st ionisation energy across periods

Answer 2

• nuclear changes increases
• same shell: similar shielding
• nuclear art increases
• atomic radius decreases
• 1st ionisation energy increases

Question 3

Comparing beryllium to boron

Answer 3

• 2p sub- shell in B has a higher energy level than the 2s in Be
• so electron is easier to remove

Question 4

Comparing nitrogen to oxygen

Answer 4

• nitrogen has 3 electrons in the 2p sub- shell, one electron in each 2p orbital.
• oxygen has 4 electrons in the 2p sub- shell, 2 paired electrons in one orbital and 1 electron in each of the other 2 2p orbitals
• paired electrons in sullied repel one another making it easier to remove an electron

Question 5

Comparing Aluminium and magnesium

Answer 5

—

Question 6

Comparing sulfur and phosphorus

Answer 6

—