Attraction and repulsion:
When you rub two different insulating materials against each other they become electrically charged.
When the materials are rubbed against each other:
- Negatively charged particles called electrons move from one material to the other
- The material that loses electrons becomes positive
- The material that gains electrons becomes negative
- Both materials gain an equal amount of charge but the charges are opposite
Two objects will repel each other if they have the same charge (P+P or N+N). They will attract each other if they have different charges.
To tell if an object is charged you need to see if it repels another object. This is because charged objects will attract small uncharged objects.