electron

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Related to Electron mass: speed of light, Planck constant, Joule, Bohr radius

electron

 [e-lek´tron]
any of the negatively charged particles arranged in orbitals around the nucleus of an atom and determining all of the atom's physical and chemical properties except mass and radioactivity. Electrons flowing in a conductor constitute an electric current; when ejected from a radioactive substance, they are beta particles.ƒ

The number of electrons revolving around the nucleus of an atom is equal to its atomic number. An atom of oxygen, for instance, which has an atomic number of 8, has eight electrons in orbit around the nucleus in a manner similar to the planets revolving around the sun in our solar system.

Electrons greatly influence the behavior of an atom toward other atoms. The combination of various elements to form compounds is brought about by the losing or gaining of electrons; the process is sometimes called “sharing” of electrons. For example, the combination of the elements sodium and chlorine produce the compound sodium chloride (table salt). This is accomplished by the transfer of one electron from the outer electron shell of the sodium atom to the outer electron shell of the chlorine atom. This combining of elements by the loss or gain of electrons is called electrovalence.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

e·lec·tron (β-),

(ē-lek'tron),
One of the negatively charged subatomic particles that orbit the positive nucleus, in one of several energy levels called shells; in mass they are estimated to be 1/1836.15 of a proton; when emitted from inside the nucleus of a radioactive substance, electrons are called β particles. A nucleus and its electrons constitute an atom.
See also: shell.
[electro- + -on]
Farlex Partner Medical Dictionary © Farlex 2012

e·lec·tron

(β-) (ĕ-lek'tron)
One of the negatively charged subatomic particles that are distributed about the positive nucleus and with it constitute the atom; in mass they are estimated to be 1/1836.15 of a proton; when emitted from inside the nucleus of a radioactive substance, electrons are called beta particles.
[electro- + -on]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

Electron

One of the small particles that make up an atom. An electron has the same mass and amount of charge as a positron, but the electron has a negative charge.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

e·lec·tron

(ĕ-lek'tron)
Negatively charged subatomic particles that orbit the positive nucleus, in one of several energy levels called shells. A nucleus and its electrons constitute an atom.
[electro- + -on]
Medical Dictionary for the Dental Professions © Farlex 2012
References in periodicals archive ?
Caption: Figure 3: The total average WIMP-electron cross section in units [[sigma].sub.0] as a function of the WIMP mass in units of the electron mass. In panel (a) the Fermi function was neglected, while in panels (b) and (c) the Fermi function F for n = 3 and Z = 50 and n = 4 and Z = 60, respectively, has been employed.
In addition, [[zeta].sub.m] = [m.sub.i]/[m.sub.e] is ratio between ion and electron masses, [[xi].sub.T] = [T.sub.e0]/[T.sub.i0] = ([P.sub.e0][n.sub.i0])/([p.sub.i0][n.sub.e0]) is the ratio between electron and ion temperatures, and [[xi].sub.V] = ([p.sub.e0][n.sub.i0])([p.sub.i0][n.sub.e0]) is the ratio between electron thermal speed and the speed of light in the brain, where C is the speed of light in free space.
where [delta][m.sup.1] and [delta][m.sup.2] are the shifts in electron mass in the first and second order in [alpha], respectively.
On the other hand, r and p are relative electron position and momentum in the center of mass coordinate system; [mu] = [m.sub.e][m.sub.p]/([m.sub.e] + [m.sub.p]) is the reduced electron mass. As seen from (9), [mathematical expression not reproducible] corresponds to the Hamiltonian of a hydrogen atom in the absence of the external field.
Consequently, the logarithm of the W/Z-boson to electron mass ratio is 41/2 + 71/2 = 12:
Based on these wavelength and energy measurements, scientists can calculate the effective electron mass for specific electron bands.
The total cross section for this spin flip is on the order of [4[pi]([gamma][e.sup.2]/[m.sub.e][c.sup.2])] = 3.6b[3] ([gamma] = -1.91 is the gyromagnetic ratio of the neutron, e is the charge of the electron, and [m.sub.e][c.sup.2] is the electron mass), which gives a spin-flip scattering probability of order 6 X [10.sup.-6].
where [D.sub.m] is the absorbed dose in the medium surrounding the cavity, [J.sub.g] is the ionization per unit mass in the cavity, [W.sub.g] is mean energy expended in the gas to produce an ion pair, and [bar.(S / [rho][).sub.m]]/[bar.(S / [rho][).sub.g]] is the ratio of the mean electron-fluence-weighted electron mass stopping power of the medium to that of the gas.
where [N.sub.e] is the number of equivalent ellipsoids in the first Brillouin zone, the volume of the unit cell is V= [a.sub.L.sup.3], [a.sub.L] is the lattice constant, m* is one of the effective masses listed in Table 1 for the appropriate band extrema, and [m.sub.0] is the free electron mass. Because eight permutations of the wave vector in the (111) direction exist, there are eight L sub-band ellipsoids with centers located near the boundary of the first Brillouin zone.
The radii [r.sub.c] (= [e.sup.2.sub.*]/m[c.sup.2]) and [r.sub.*] (= [e.sup.2.sub.*]/[m.sub.*][c.sup.2]) are the electron and Planck-particle Compton radii respectively and m is the electron mass. The magnitudes of r, and m, are equal to the Planck length and mass respectively [4, p.
where [m.sub.c] is the electron mass. The tensor polarizability is zero for levels with J [less than] 1, such as the [Hg.sup.+] [5d.sub.10][6s.sub.2][S.sub.1/2] level.