Pearson Edexcel IAL Chemistry 3.1 Evidence for ions
Practise using conductivity, electron-density maps and ion-migration observations to justify the presence and movement of ions.
- Syllabus
- First assessment 2019
- Course
- Chemistry YCH11
- Level
- AS
Practise using conductivity, electron-density maps and ion-migration observations to justify the presence and movement of ions.
This question is about magnesium, magnesium oxide and magnesium sulfate.
The table gives some data about the electrical conductivity of magnesium and magnesium oxide.

Explain the similarities and differences in the electrical conductivity of the two substances.
An answer that makes reference to the following points:
- Mg: has delocalised electrons (that are free to move)
(1) when solid and liquid
- MgO : ions are only free to move when liquid
(1)
Allow has electrons that are free to move
Allow ions are not free to move when solid Ignore ions/electrons carrying charge
(2)