What particle has a negative electric charge?

The particle that has a negative electric charge is the electron. An electron carries one negative elementary charge, written −e, and is symbolized as e⁻. It is an elementary particle in the lepton family and is found in atoms outside the positively charged nucleus.

In a neutral atom, the number of electrons normally equals the number of protons. If an atom gains electrons, it becomes a negatively charged ion called an anion; if it loses electrons, it becomes a positively charged cation. The movement of electrons through a material is also the basis of ordinary electric current in metals.

The electron was identified as a particle through experiments by J. J. Thomson in 1897, although earlier scientists had proposed the idea of electrical units. Its mass is much smaller than a proton’s—about 1/1836 as large—so electrons are responsible for most chemical bonding and atomic behavior without contributing much atomic mass.

A neutron has no net electric charge, while a proton is positive. Quarks can have fractional charges, but “quark” is not a single particle with one universal charge.