Fr.: signal électromagnétique
Information transmitted by means of a modulated current or an electromagnetic wave and received by telephone, radio, television, etc.
Fr.: spectre électromagnétique
The range of frequencies over which electromagnetic waves are propagated. → electromagnetic radiation.
Fr.: théorie électromagnétique
electromagnetic theory of light
negare-ye barqâmeqnâti-ye nur
Fr.: théorie électromagnétique de la lumière
The theory describing light as a wave phenomenon resulting from the combination of two electric and magnetic fields vibrating transversely and mutually at right angles. → electromagnetic radiation; → electromagnetic wave; → Maxwell's equations.
Fr.: onde électromagnétique
A wave produced by oscillation or acceleration of an electric charge. → electromagnetic radiation.
1) The science dealing with the physical relations between → electricity
and → magnetism. Same as
→ electromagnetic theory.
electromotive force (EMF)
niru-ye barqrân (#)
Fr.: force électromotrice
The force, analogous to a pressure, which maintains a flow of electricity through a closed circuit. It is the algebraic sum of the → potential differences acting in the circuit. The unit of electromotive force is the → volt.
The → elementary particle that possesses the smallest possible negative → electric charge. This structureless particle has an intrinsic → spin (1/2), a mass of 9.109 382 91 (40) x 10-31 kg, and an electric charge of 1.602 176 565(35) × 10-19 → coulombs, or 4.803 204 51(10) × 10-10 → esu.
Fr.: affinité électronique
The amount of energy released or absorbed in the process in which an electron is added to a neutral atom or molecule in gaseous state to form a negative ion.
Fr.: capture d'électron
A process whereby an → unstable atom becomes stable. In this process, an → electron in an atom's inner shell is drawn into the → nucleus where it combines with a → proton, forming a → neutron and a → neutrino. The neutrino escapes from the atom's nucleus. The result is an element change, because the atom loses a proton. For example, an atom of → carbon (with 6 protons) becomes an atom of → boron (with 5 protons). Electron capture is also called K-capture since the captured electron usually comes from the atom's K-shell. See also → neutronization.
bâr-e elektron (#)
Fr.: charge de l'électron
Fr.: configuration électronique
Of an atom, a form of notation which shows how the electrons are distributed among the various atomic orbital and energy levels. The format consists of a series of numbers, letters and superscripts. For example, 1s2 2s2 2p3 means: 2 electrons in the 1s subshell, 2 electrons in the 2s subshell, and 3 electrons in the 2p subshell.
vâgeni-ye elektron (#)
Fr.: dégénérescence des électrons
A → degenerate matter in which electrons are very tightly packed together, as in a white dwarf, but cannot get closer than a certain limit to each other, because according to quantum mechanics laws (→ Pauli exclusion principle) the lowest energy levels can be occupied by only one electron. Therefore, electrons are forced into high energy states. And the significant pressure created by these high energy electrons supports white dwarf stars against their own gravity.
cagâli-ye elektroni (#)
Fr.: densité électronique
parâš-e elekroni (#)
Fr.: diffraction des électrons
A diffraction phenomenon resulting from the passage of electrons through matter, analogous to the diffraction of visible light. This phenomenon is the main evidence for the existence of waves associated with elementary particles; → de Broglie wavelength.
jerm-e elekron (#)
Fr.: masse de l'électron
The mass of an electron, which is 9.109 382 91 × 10-28 g.
Fr.: rayon de l'électron
puste-ye elekroni (#)
Fr.: couche éléctronique
Any of up to seven energy levels on which an electron may exist within an atom, the energies of the electrons on the same level being equal and on different levels being unequal. The number of electrons permitted in a shell is equal to 2n2. A shell contains n2 orbitals, and n subshells.
damâ-ye elektroni (#)
Fr.: température électronique
1) The temperature of electrons in an interstellar ionized nebula (e.g. in
→ H II regions and
→ planetary nebulae) as determined by characteristic
→ emission lines (optical
→ forbidden lines or
→ radio recombination lines).
electron volt (eV)