electron


electron
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]
- Auger e. an e. ejected from an orbital by photoelectric interaction with a photon emitted when another e., in a higher energy orbital, passed from a higher to a lower energy level; the Auger e. recoils with energy equal to the characteristic radiation less the difference in shell binding energies. See photoelectric effect, transition e..
- emission e. a beta particle resulting from radioactive decay.
- internal conversion e. an e., similar to an Auger e., released from one of the e. orbits of the atom upon activation by a gamma ray from that atom's nucleus; the e. has kinetic energy equal to the net energy transition of the disintegration.
- positive e. SYN: positron.
- transition e. an e. that moves from one energy level to another to fill a vacancy in a shell, with the emission of characteristic radiation.
- valence e. one of the electrons that take part in chemical reactions of an atom.

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elec·tron i-'lek-.trän n an elementary particle consisting of a charge of negative electricity equal to about 1.602 × 10-19 coulomb and having a mass when at rest of about 9.109534 × 10-28 gram or about 1/1836 that of a proton

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elec·tron (e-lekґtron) [Gr. ēlektron amber, because an electric charge can be produced in amber by rubbing] an elementary particle possessing the unit quantum of (negative) electric charge, 1.6 Ч 10−19 coulomb, with mass 1/1836 that of a proton, or 9.11 Ч 10−31 kilogram. Electrons can exist as atomic constituents or in the free state; flowing in a conductor they constitute an electric current; when ejected from a radioactive substance, they constitute beta rays; and when revolving about the nucleus of an atom they determine all of its physical and chemical properties except mass and radioactivity. Symbol e or e. See also atom.

Medical dictionary. 2011.

Look at other dictionaries:

  • ÉLECTRON — L’électron est une particule élémentaire stable. Il possède une charge électrique négative, une très petite masse (près de 2 000 fois plus petite que celle de l’atome le plus léger: l’hydrogène), et un moment angulaire propre appelé spin, auquel… …   Encyclopédie Universelle

  • Éléctron — Électron Électron Sections transversales des premières orbitales de l atome d hydrogène, le code de couleurs représentant l amplitude de probabilité de l électron Propriétés générales …   Wikipédia en Français

  • Electrón — Saltar a navegación, búsqueda Electrón e− Representación en corte transversal de los orbitales s, p y d del átomo de hidrógeno para los tres primeros números cuánticos. La intensidad del color indica la densidad de …   Wikipedia Español

  • electron — ELECTRÓN, electroni, s.m. Particulă elementară cu cea mai mică sarcină electrică cunoscută în natură şi care intră în alcătuirea atomilor tuturor substanţelor. – Din fr. électron. Trimis de claudia, 13.09.2007. Sursa: DEX 98  ELECTRÓN s. (fiz.)… …   Dicționar Român

  • Electron — E*lec tron, n. [NL., fr. Gr. h lektron. See {Electric}.] 1. Amber; also, the alloy of gold and silver, called {electrum}. [archaic] [1913 Webster] 2. (Physics & Chem.) one of the fundamental subatomic particles, having a negative charge and about …   The Collaborative International Dictionary of English

  • electron — coined 1891 by Irish physicist George J. Stoney (1826 1911) from ELECTRIC (Cf. electric) + on, as in ION (Cf. ion) (q.v.). Electron microscope translates Ger. Elektronenmikroskop (1932) …   Etymology dictionary

  • Electron — См. Электрон Термины атомной энергетики. Концерн Росэнергоатом, 2010 …   Термины атомной энергетики

  • electrón — 1. partícula elemental cargada negativamente, con carga específica, masa y spin. El número de electrones que rodea al núcleo de un átomo es igual al número atómico de esa sustancia. Los electrones pueden ser compartidos o intercambiados por dos… …   Diccionario médico

  • eléctron — |ét| s. m. [Física] Corpúsculo que contém a mínima carga de eletricidade negativa, constituinte universal da matéria. = ELETRÃO • [Portugal] Plural: eléctrones.   ♦ [Portugal] Grafia de elétron antes do Acordo Ortográfico de 1990.   ♦ Grafia no… …   Dicionário da Língua Portuguesa

  • electrón — sustantivo masculino 1. Área: física Partícula elemental de un átomo cargada negativamente …   Diccionario Salamanca de la Lengua Española

  • electrón — (Del gr. ἤλεκτρον, ámbar, con acentuación fr.). m. Fís. Partícula elemental más ligera que forma parte de los átomos y que contiene la mínima carga posible de electricidad negativa …   Diccionario de la lengua española


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