A property of some elementary particles, such as electrons or protons. Electric charge can be positive or negative and cannot be destroyed or created. An electron has a unit negative charge of 1.602176634 × 10⁻¹⁹ coulomb, while a proton has the same charge but positive. The electric charge determines how a charged particle will behave in an electric or magnetic field. A particle with no charge will not react to such a field, while charged particles will change their trajectory. Particles with an electric charge attract or repel each other with Coulomb forces.