Electron

Subatomic particle with negative electric charge

For other uses, see Electron (disambiguation).

Electron

The electron is a subatomic particle with a negative electric charge. It is one of the fundamental constituents of matter, playing a crucial role in electricity, magnetism, and chemical bonding. Electrons are part of the lepton family of particles and are considered elementary particles because they are not composed of smaller particles.

Standard Model of Elementary Particles

History

The concept of the electron emerged from studies of electricity in the 19th century. The term "electron" was coined by George Johnstone Stoney in 1891, but it was J.J. Thomson who is credited with the discovery of the electron in 1897 through his experiments with cathode rays.

J.J. Thomson, discoverer of the electron

Properties

Electrons have a rest mass of approximately 9.109 × 10⁻³¹ kilograms, which is about 1/1836 of the mass of a proton. They carry a negative electric charge of approximately −1.602 × 10⁻¹⁹ coulombs. Electrons exhibit both particle and wave properties, a duality that is a fundamental aspect of quantum mechanics.

Wave properties of electrons

Quantum Mechanics

In the realm of quantum mechanics, electrons are described by wave functions and can exist in various quantum states. The behavior of electrons in atoms is described by atomic orbitals, which are regions of space where there is a high probability of finding an electron.

s orbital

Atomic orbital clouds

Role in Atoms

Electrons are bound to the nucleus of an atom by the electromagnetic force. They occupy energy levels or shells around the nucleus, and their arrangement determines the chemical properties of an element. The Bohr model of the atom, proposed by Niels Bohr, was an early attempt to describe electron behavior in atoms.

Bohr model of the atom

Interactions

Electrons interact with other particles through the electromagnetic force. They can also emit or absorb photons, which are quanta of light, during transitions between energy levels. In addition, electrons can form virtual particles in the quantum field theory framework.

Virtual pairs near an electron

Applications

Electrons are fundamental to the operation of many modern technologies, including semiconductors, transistors, and cathode ray tubes. They are also essential in the study of electricity and magnetism, as they are the primary charge carriers in conductors.

Cyclotron motion of electrons

Lorentz Force

The motion of electrons in a magnetic field is described by the Lorentz force, which is the force experienced by a charged particle moving through a magnetic field.

Lorentz force on a charged particle

Related pages

• Proton
• Neutron
• Photon
• Quantum mechanics
• Electricity
• Magnetism