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This radiation is in the form of beta (β) particles, which are high-energy electrons or positrons ejected from a nucleus in a process known as beta decay. There are two forms of beta decay, β− and β+, which respectively give rise to the electron and positron.
In β−-decay, a neutron is converted into a proton, an electron and an electron-type antineutrino (the antiparticle of the neutrino):
In β+-decay—observed in proton-rich nuclei—a proton is converted into a neutron, a positron and an electron-type neutrino:
Due to the presence of the neutrino, the atom and the beta particle do not usually recoil in opposite directions. This observation is in fact what led Wolfgang Pauli to postulate the existence of neutrinos in order to prevent violation of conservation of energy and momentum laws. Beta decay is mediated by the weak nuclear forceThe weak nuclear force or weak interaction is one of the four fundamental forces of nature. It is most commonly seen in beta decay and the associated radioactivity. The predicate weak derives from the fact that the field strength is some 109 times less th.
Beta particles generally have a range about ten times as far as alpha particleAlpha particles or alpha rays are a form of particle radiation which are highly ionizing and have low penetration. They consist of two protons and two neutrons bound together into a particle that is identical to a helium nucleus, and can be written as He2s and an ionizing power about a tenth of that of alpha particles. They are stopped completely by a few millimeters of aluminiumAluminium (or aluminum in North American English) is the chemical element in the periodic table with the symbol Al and atomic number 13. A silvery and ductile member of the poor metal group of elements, aluminium is found primarily as the ore bauxite and.
The electron gun inside a televisionSee TV (disambiguation) for other uses and Television (band) for the rock band Television is a telecommunication system for broadcasting and receiving moving pictures and sound over a distance. The term has come to refer to all the aspects of television p tube could also be considered a source of beta radiation, which is absorbed by the phosphorA phosphor is a substance that can exhibit the phenomenon of fluorescence (glowing during absorption of radiation of another kind) or phosphorescence (sustained glowing without further stimulus). The chemical element phosphorus (Greek. phosphoros meaning coating inside the tube to create lightLight is electromagnetic radiation with a wavelength that is visible to the eye, or in a more general sense, any electromagnetic radiation in the range from infrared to ultraviolet. The three basic dimensions of light (and of all electromagnetic radiation.