Electric Charges Electric charges have four very important properties. Like charges repel one another and unlike charges attract one another. Charge is quantized. Electrical charge is always conserved. The force between charged particles varies as the inverse square of their separation.
Conductors are materials in which charges move freely.
Insulators are materials that don't readily transport charge. Coulomb's Law Coulomb's law describes the electrostatic force between two stationary, charged particles which are seperated by a distance r . The charge on an electron or proton is the smallest unit of charge known to exist in nature. The electric field is directed radially toward a negative charge and radially outward from a positive charge. The electric field due to a group of charges can be found using the superposition principle .