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Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha, beta, and gamma decay.
in physics and biology radionuclide X-ray fluorescence spectrometry is used to determine chemical composition of the compound. Radiation from a radionuclide source hits the sample and excites characteristic X-rays in the sample. This radiation is registered and the chemical composition of the sample can be determined from the analysis of the ...
A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example carbon-13 with 6 protons and 7 neutrons. The nuclide concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, while the isotope concept (grouping all atoms of each element) emphasizes ...
The study of proton emission has aided the understanding of nuclear deformation, masses and structure, and it is an example of quantum tunneling. Two examples of nuclides that emit neutrons are beryllium-13 (mean life 2.7 × 10 −21 s) and helium-5 (7 × 10 −22 s). Since only a neutron is lost in this process, the atom does not gain or lose ...
Such nuclides are considered to be "stable" until a decay has been observed in some fashion. For example, tellurium-123 was reported to be radioactive, but the same experimental group later retracted this report, and it presently remains observationally stable. The next group is the primordial radioactive nuclides.
The center of the atom contains a tight ball of neutrons and protons, which is held together by the strong nuclear force, unless it is too large. Unstable nuclei may undergo alpha decay, in which they emit an energetic helium nucleus, or beta decay, in which they eject an electron (or positron). After one of these decays the resultant nucleus ...
), have two odd–even stable isotopes each. This makes a total of 30×1 + 9×2 = 48 stable odd–even isotopes. The lightest example of this type of nuclide is 1 1 H (protium) as zero is an even number while the heaviest example is 205 81 Tl. There are also five primordial long-lived radioactive odd–even isotopes, 87 37 Rb, [9] 115 49 In ...
Phases of nuclear matter with equal numbers of neutrons and protons; Compare with Siemens & Jensen. [1]Nuclear matter is an idealized system of interacting nucleons (protons and neutrons) that exists in several phases of exotic matter that, as of yet, are not fully established. [2]