Global InformationElectron information
 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 | 9.1093837015(28)×10−31 kg[6] 5.48579909065(16)×10−4 Da[7] [1822.888486209(53)]−1 Da[b] 0.51099895000(15) MeV/c2[8] |
| Mean lifetime | > 6.6×1028 years[9] (stable) |
| Electric charge | −1 e −1.602176634×10−19 C[10] |
| Magnetic moment | −9.2847647043(28)×10−24 J⋅T−1[11] −1.00115965218128(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 |
|---|
 |
The electron (
e−
or
β−
) is a subatomic particle with a negative one elementary electric charge.[13] Electrons belong to the first generation of the lepton particle family,[14] and are generally thought to be elementary particles because they have no known components or substructure.[1] The electron's mass is approximately 1/1836 that of the proton.[15] Quantum mechanical properties of the electron include an intrinsic angular momentum (spin) of a half-integer value, expressed in units of the reduced Planck constant, ħ. Being fermions, no two electrons can occupy the same quantum state, per the Pauli exclusion principle.[14] Like all elementary particles, electrons exhibit properties of both particles and waves: They can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Broglie wavelength for a given energy.
Electrons play an essential role in numerous physical phenomena, such as electricity, magnetism, chemistry, and thermal conductivity; they also participate in gravitational, electromagnetic, and weak interactions.[16] Since an electron has charge, it has a surrounding electric field; if that electron is moving relative to an observer, the observer will observe it to generate a magnetic field. Electromagnetic fields produced from other sources will affect the motion of an electron according to the Lorentz force law. Electrons radiate or absorb energy in the form of photons when they are accelerated.
Laboratory instruments are capable of trapping individual electrons as well as electron plasma by the use of electromagnetic fields. Special telescopes can detect electron plasma in outer space. Electrons are involved in many applications, such as tribology or frictional charging, electrolysis, electrochemistry, battery technologies, electronics, welding, cathode-ray tubes, photoelectricity, photovoltaic solar panels, electron microscopes, radiation therapy, lasers, gaseous ionization detectors, and particle accelerators.
Interactions involving electrons with other subatomic particles are of interest in fields such as chemistry and nuclear physics. The Coulomb force interaction between the positive protons within atomic nuclei and the negative electrons without allows the composition of the two known as atoms. Ionization or differences in the proportions of negative electrons versus positive nuclei changes the binding energy of an atomic system. The exchange or sharing of the electrons between two or more atoms is the main cause of chemical bonding.[17]
In 1838, British natural philosopher Richard Laming first hypothesized the concept of an indivisible quantity of electric charge to explain the chemical properties of atoms.[3] Irish physicist George Johnstone Stoney named this charge "electron" in 1891, and J. J. Thomson and his team of British physicists identified it as a particle in 1897 during the cathode-ray tube experiment.[5]
Electrons participate in nuclear reactions, such as nucleosynthesis in stars, where they are known as beta particles. Electrons can be created through beta decay of radioactive isotopes and in high-energy collisions, for instance, when cosmic rays enter the atmosphere. The antiparticle of the electron is called the positron; it is identical to the electron, except that it carries electrical charge of the opposite sign. When an electron collides with a positron, both particles can be annihilated, producing gamma ray photons.
- ^ a b Cite error: The named reference
prl50was invoked but never defined (see the help page). - ^ Cite error: The named reference
farrarwas invoked but never defined (see the help page). - ^ a b Cite error: The named reference
arabatziswas invoked but never defined (see the help page). - ^ Cite error: The named reference
buchwald1was invoked but never defined (see the help page). - ^ a b Cite error: The named reference
thomsonwas invoked but never defined (see the help page). - ^ "2018 CODATA Value: electron mass". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2019-05-20.
- ^ "2018 CODATA Value: electron mass in u". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2020-06-21.
- ^ "2018 CODATA Value: electron mass energy equivalent in MeV". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2022-07-11.
- ^ Agostini, M.; et al. (Borexino Collaboration) (2015). "Test of electric charge conservation with Borexino". Physical Review Letters. 115 (23): 231802. arXiv:1509.01223. Bibcode:2015PhRvL.115w1802A. doi:10.1103/PhysRevLett.115.231802. PMID 26684111. S2CID 206265225.
- ^ "2018 CODATA Value: elementary charge". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2019-05-20.
- ^ "2018 CODATA Value: electron magnetic moment". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2022-09-10.
- ^ "2018 CODATA Value: electron magnetic moment to Bohr magneton ratio". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2022-11-15.
- ^ Coffey, Jerry (10 September 2010). "What is an electron?". Archived from the original on 11 November 2012. Retrieved 10 September 2010.
- ^ a b Curtis, L.J. (2003). Atomic Structure and Lifetimes: A conceptual approach. Cambridge University Press. p. 74. ISBN 978-0-521-53635-6. Archived from the original on 2020-03-16. Retrieved 2020-08-25.
- ^ Cite error: The named reference
nist_codata_muwas invoked but never defined (see the help page). - ^ Cite error: The named reference
anastopoulos1was invoked but never defined (see the help page). - ^ Cite error: The named reference
Paulingwas invoked but never defined (see the help page).
Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).