# Elementary Charge

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## elementary charge

[‚el·ə′men·trē ‚chärj]
(physics)
An electric charge such that the electric charge of any body is an integral multiple of it, equal to the electron charge.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

## Elementary Charge

e, the smallest electric charge known in nature. The existence of the elementary charge was first mentioned with certainty by the British scientist G. Stoney in 1874. Stoney’s hypothesis was based on the laws of electrolysis established by M. Faraday (1833–34). In 1881, Stoney was the first to calculate the magnitude of the electric charge of a univalent ion, equal to e = F/NA, where F is the faraday constant and NA is Avogadro’s number. In 1911 the elementary charge was established by R. Millikan through direct measurements.

The presently accepted value of e is

e = (4.803242 ± 0.000014) × 10–10 cgse units

= (1.6021892 ± 0.0000046) × 10–19 coulomb

The magnitude of the elementary charge is the constant of the electromagnetic interactions, which appears in all equations of microscopic electrodynamics. The elementary charge is exactly equal to the electric charge of the electron, proton, and nearly all other charged elementary particles, which by virtue of this fact are the material carriers of the smallest charge in nature.

The elementary charge cannot be destroyed, and it is this fact that constitutes the content of the law of conservation of electric charge on the microscopic level. There is a positive and a negative elementary charge; in this case, an elementary particle and its antiparticle have charges of opposite sign. The electric charge of any microsystem and of macroscopic bodies is always equal to an integral multiple of the quantity e or to zero. The reason for such “quantization” of charge has not been established. One hypothesis is based on the existence of Dirac monopoles (seeMAGNETIC MONOPOLE). A hypothesis positing the existence of particles with fractional electric charges—quarks—has been much discussed since the 1960’s (seeQUARK and ).

### REFERENCE

Millikan, R. A. Eleklrony (+ i –), protony, fotony, neitrony i kosmicheskie luchi. Moscow-Leningrad, 1939. (Translated from English).

L. I. PONOMAREV

References in periodicals archive ?
The new definitions will be based on fixed numerical values of the Planck constant (h), the elementary charge (e), the Boltzmann constant (k), and the Avogadro constant (NA), respectively.
These include the Planck constant, which describes the scale of the quantum realm; the Boltzmann constant, which relates temperature and energy; the Avogadro constant, which sets the number of atoms or molecules that make up a mole; and the magnitude of the charge of an electron or proton, also known as the elementary charge. The new units will be based on the modern understanding of physics, including the laws of quantum mechanics and Einstein's theory of special relativity.
When crossing the initial surface of our world, an open contour (vortical tube) actually forms an elementary charge (according to Wheeler).
in which C is the conversion constant, k is the total number of ions in solution and the elementary charge on the surface, [q.sub.i] is the electric quantity held by ion i or its elementary charge, [r.sub.0] is the reference point (taken as the pore center point here) at which the voltage is taken to zero, and r is the position of ion i.
Euler's constant 1/(lim(x-->infinity) Euler's constant ((1-(1/x))^x)) W^(k/S) Euler's constant [W=number of microstates; k=Boltzmann constant; S=entropy] F/[N.sub.A] Elementary charge [F=Faraday constant; NA Avogadro constant] 1.6022*(10^-19)(C) Elementary charge F ma Force [m=mass; a=acceleration] v Frequency of a wave [v=frequency] v/lambda] Frequency of a wave [v=velocity; [lambda]=wavelength] c/[lambda] Frequency of a wave in a vacuum [c=speed of light; [lambda]=wavelength] E/h Frequency of a wave [E=energy; h=Planck's constant] e[N.sub.A] Faraday constant [[N.sub.A]=Avogadro constant; e=elementary charge] 96485.3365 ...
A remarkable feature of a single chain is that the individual electrons, which behave as an elementary charge combined with magnetic spin, co-operate in concert to separate into independent spin and charge parts.
e is the elementary charge, the electron rest mass, and c the speed of light in vacuum.
where a is the radius of the conductors, v "the drift velocity of the charges (in practice electrons, and the speed is much lower than the speed of light)"  *, q the elementary charge, and N the free electron density in the conductors.
where g is the PMT gain, e is the elementary charge, Q ([lambda]) is the quantum efficiency of the PMT photocathode at wavelength [lambda], and [E.sub.F] ([lambda]) is the flux of fluorescence photons per unit wavelength at the wavelength [lambda].
That is, Planck's familiar constant, h, which has been shown experimentally to play an indispensable role in the microphysical realm, and a second, more diminutive "action" formed from two of the fundamental constants of quantum mechanics, namely, [e.sup.2]/c--the ratio of the square of the elementary charge to the velocity of light, which has the value 7.6957 x [10.sup.-37] J s.

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