Electron
Electron
Experiments with Crookes tube first demonstrated the
particle nature of electrons. In this illustration, the profile
of the cross-shaped target is projected against the tube
face at right by a beam of electrons.[1]
Composition: Elementary particle[2]
Family:
Fermion
Group:
Lepton
Generation:
First
Interaction:
Gravity, Electromagnetic,
Weak
Antiparticle:
Positron (also called
antielectron)
Theorized:
Richard Laming (1838–51),[3]
G. Johnstone Stoney (1874)
and others.[4][5]
Discovered:
J. J. Thomson (1897)[6]
Symbol(s):
e−, β−
Mass:
9.10938215(45)×10−31 kg[7]
5.4857990943(23)×10−4 u[7]
[1822.88850204(77)]-1 u[note 1]
0.510998910(13) MeV/c2[7]
Electric
charge:
−1 e[note 2]
−1.602176487(40)×10−19 C[7]
Magnetic
moment:
−1.00115965218111 μB[7]
Spin:
1⁄2
The electron is a subatomic particle that
carries a negative electric charge. It has no
known substructure and is believed to be a
point particle.[2] Electrons participate
in
gravitational, electromagnetic and weak in-
teractions. Like its rest mass and elementary
charge, the intrinsic angular momentum (or
spin) of an electron has a constant value. In
the collision of an electron and a positron,
the electron’s antiparticle, both are annihil-
ated. An electron–positron pair can be pro-
duced from gamma ray photons with suffi-
cient energy.[8]
The concept of an indivisible amount of
electric charge was theorized to explain the
chemical properties of atoms, beginning in
1838 by British natural philosopher Richard
Laming;[4] the name electron was introduced
for this charge in 1894 by Irish physicist Ge-
orge Johnstone Stoney. The electron was
identified as a particle in 1897 by J. J. Thom-
son and his team of British physicists.[6][9]
Electrons are identical particles that belong
to the first generation of the lepton particle
family. Electrons have quantum mechanical
properties of both a particle and a wave, so
they can collide with other particles and be
diffracted like light. Each electron occupies a
quantum state that describes its random be-
havior up