electrostatics

Study of stationary electric charges and their fields (not currents). See static electricity.

Charged materials behave differently if they are brought near to each other. Materials of like charge, that is both positive or both negative, will move away from each other (repelled by electrostatic force). Materials of opposite charge, that is one positive and one negative, brought close together will move towards each other (attracted by electrostatic force).

An electroscope is an instrument that detects charges on objects that have been charged by static electricity.