Electron

Electron

Hydrogen atomic orbitals at different energy levels. The more opaque areas are where one is most likely to find an electron at any given time.
Composition	Elementary particle[1]
Statistics	Fermionic
Family	Lepton
Generation	First
Interactions	Weak, electromagnetic, gravity
Symbol	e− , β−
Antiparticle	Positron[a]
Theorized	Richard Laming (1838–1851),[2] G. Johnstone Stoney (1874) and others.[3][4]
Discovered	J. J. Thomson (1897)[5]
Mass	9.1093837139(28)×10−31 kg‍[6] 5.485799090441(97)×10−4 Da‍[7] [1822.888486209(53)]−1 Da[b] 0.51099895069(16) MeV/c2‍[8]
Mean lifetime	> 6.6×1028 years[9] (stable)
Electric charge	−1 e −1.602176634×10−19 C‍[10]
Magnetic moment	−9.2847646917(29)×10−24 J⋅T−1‍[11] −1.00115965218046(18) μB‍[12]
Spin	⁠ 1 /2⁠ ħ
Weak isospin	LH: −⁠ 1 /2⁠, RH: 0
Weak hypercharge	LH: −1, RH: −2

Standard Model of particle physics
Elementary particles of the Standard Model
Background Particle physics Standard Model Quantum field theory Gauge theory Spontaneous symmetry breaking Higgs mechanism
Constituents Electroweak interaction Quantum chromodynamics CKM matrix Standard Model mathematics
Limitations Strong CP problem Hierarchy problem Neutrino oscillations Physics beyond the Standard Model
Scientists Rutherford Thomson Chadwick Bose Sudarshan Davis Jr Anderson Fermi Dirac Feynman Rubbia Gell-Mann Kendall Taylor Friedman Powell Anderson Glashow Iliopoulos Lederman Maiani Meer Cowan Nambu Chamberlain Cabibbo Schwartz Perl Majorana Weinberg Lee Ward Salam Kobayashi Maskawa Mills Yang Yukawa 't Hooft Veltman Gross Pais Pauli Politzer Reines Schwinger Wilczek Cronin Fitch Vleck Higgs Englert Brout Hagen Guralnik Kibble de Mayolo Lattes Zweig
v t e

The electron (e⁻
, or β⁻
in nuclear reactions) is a subatomic particle with a negative one elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up and down quarks.

Electrons are extremely lightweight particles that orbit the positively charged nucleus of atoms. Their negative charge is balanced by the positive charge of protons in the nucleus, giving atoms their overall neutral charge. Ordinary matter is composed of atoms, each consisting of a positively charged nucleus surrounded by a number of orbiting electrons equal to the number of protons. The configuration and energy levels of these orbiting electrons determine the chemical properties of an atom. Electrons are bound to the nucleus to different degrees. The outermost or valence electrons are the least tightly bound and are responsible for the formation of chemical bonds between atoms to create molecules and crystals. These valence electrons also facilitate all types of chemical reactions by being transferred or shared between atoms. The inner electron shells make up the atomic core.

Electrons play a vital role in numerous physical phenomena due to their charge and mobile nature. In metals, the outermost electrons are delocalised and able to move freely, accounting for the high electrical and thermal conductivity of metals. In semiconductors, the number of mobile charge carriers (electrons and holes) can be finely tuned by doping, temperature, voltage and radiation - the basis of all modern electronics.

Electrons can be stripped entirely from their atoms to exist as free particles. As particle beams in a vacuum, free electrons can be accelerated, focused and used for applications like cathode ray tubes, electron microscopes, electron beam welding, lithography and particle accelerators that generate synchrotron radiation. Their charge and wave-particle duality make electrons indispensable in the modern technological world.

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