AQA GCSE Physics (9-1): Static Electricity.

Follow up questions:
1) How can you cause a negative charge to build up on an insulator?
2) How can you cause a positive charge to build up on an insulator?
3) Why is an insulator required when building up static electricity?

answers below:

1) An insulator will build up a negative charge if you add electrons to it, usually via friction.
2) An insulator builds up positive charge due to electrons being removed from it. The positive protons do not move so the object will be left with a positive charge.
3) An insulator does not allow electrons to move through them, holding them in one place.