Ionisation Energy

Question 1

Definition of ionisation energy (first ie)

Answer 1

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

Question 2

Factors affecting ionising energy

Answer 2

• atom radius
• number of protons
• Electron shielding

Question 3

What does first ionising energy mean

Answer 3

To remove the 1st electron

Question 4

What does second ionising energy mean

Answer 4

To remove the second electron.

Question 5

Example of 1st and 2nd
Ionising energy of sodium
Must include state symbols

Answer 5

1st). Na(g) —> Na+(g) + e-
2nd). Na+(g) —> Na2+ + e-

Question 6

Why does the ie go down in some groups on the periodic table

Answer 6

There are more protons
More electron shielding
Bigger atomic radius so weaker attraction between the nucleus and the electrons

Question 7

Why does the ie increase as you go along the periods in the periodic table

Answer 7

Smaller atomic radius
More protons
Stronger attraction between nucleus and electrons

Question 8

Why is there a dip in the trend between group 2 and 3

Answer 8

Magnesium electron from s orbitaland aluminium electron from P orbital
P-orbital has higher energy than s

Question 9

Why is there a dip in the trend between group 5 and 6

Answer 9

P electron from orbital with one electron
S electron from orbital with two electrons
More electron re pulsing with another electron in s orbital