Electron

An electron is a fundamental subatomic particle carrying a negative electrical charge. It orbits the nucleus of an atom in electron shells, where its behavior is governed by quantum mechanics rather than classical physics. Electrons are among the lightest known particles, about 1/1836th the mass of a proton.

The electron's discovery in 1897 revolutionized our understanding of matter and electricity. Its movement through materials creates electric current, making it essential to all electronics, magnetism, and chemistry. Electrons participate in chemical bonds, determining how atoms combine and react—the foundation of periodic chemistry.

In atoms, electrons occupy discrete energy levels, jumping between them by absorbing or emitting photons (particles of light). This explains atomic spectra and powers technologies from LEDs to X-rays. In conductors like copper, electrons flow freely; in insulators, they're bound tightly.

The electron's nature bridges particle and wave physics—a duality that remains one of quantum mechanics' most profound mysteries. Modern understanding comes from quantum field theory, which treats electrons as excitations in an underlying field.

Related

Photon, Proton, Neutron, Atom, Electric charge, Quantum mechanics