Molar Ionisation energy

Question 1

What is the first molar ionisation energy?

Answer 1

the energy required to remove 1 mole of electrons from 1 mole of gaseous atoms (kj/mol)

Question 2

what does the amount of energy depend on?

Answer 2

• nuclear charge:Increase = higher IE
  -shielding: increase = lower IE
  -atomic radius (distance): increase = lowers IE

Question 3

what is the general equation?

Answer 3

Question 4

trend down a group

Answer 4

• atomic radius increases
  -distance between the nucleus and outer electron increases
  -shielding increases
  -attraction between the nucleus and outer electron decreases
• less energy required to remove the outer electron

Question 5

trend across a period

Answer 5

• nuclear charge increases (adding a proton each time)
• no change in the amount of shielding
  -no change in distance of the outer electron and nucleus
• attraction between outer electrons and nucleus increases
• more energy is needed to remove the outer electron

Question 6

what groups are the exceptions

Answer 6

• between groups 2 and 3 e.g Be/B and Mg/Al
• between groups 5 and 6 : N/O and P/S

Question 7

explanation between groups 2 and 3

Answer 7

• the outer electron in (element) is in the () orbital and the outer electron in (element) is in the () orbital
• the electron in the () orbital has high energy level
• less energy is required to remove the electron

Question 8

explanation between groups 5 and 6

Answer 8

• the outer electron in element () is PAIRED with another in the () orbital
• the outer electron in () is not
• REPULSION between the paired electrons in () means that less energy is required to remove it

Question 9

why is there a large drop in the graph

Answer 9

Due to new energy level, starting a group again

Question 10

what is the definitiokn of succcessfive IE

Answer 10

The energy required to remove electrons one by one from the same atom.
only removing one electron at a time.

Question 11

explain the trend of the graph

Answer 11

• general increase in IE due to increasing effective charge in the nucleus
• large ‘jumps’ caused by electrons being taken from an energy level that is closer to the nucleus
• decrease distance and shielding = stronger attraction

Question 12

what is the patter of SIE

Answer 12

group 1 = large jump between successive IE 1 and 2
group 2 - large jump between 2 and 3 etc