Home > Encyclopedia of Science > Electron

• Electron energy levels
• Words to Know
• Electron properties
• History
• Quantum Number
• The positron

The electron is a subatomic (smaller than an atom) particle that carries a single unit of negative electricity. All matter consists of atoms that, in turn, contain three very small particles: protons, neutrons, and electrons. Of these three, only electrons are thought to be fundamental particles, that is, incapable of being broken down into simpler particles.

The presence or absence of an excess of electrons is responsible for all electrical phenomena. Suppose a metal wire is connected to two ends of a battery. Electrical pressure from electrons within the battery force electrons in atoms of the metal to flow....