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This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
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.
Every known isotope of the remaining 25 elements is highly radioactive; these are used in academic research and sometimes in industry and medicine. [e] Some of the heavier elements in the periodic table may be revealed to have yet-undiscovered isotopes with longer lifetimes than those listed here. [f] About 338 nuclides are found naturally on ...
Radioactive nonprimordial, but naturally occurring on Earth. 61 347 Carbon-14 (and other isotopes generated by cosmic rays) and daughters of radioactive primordial elements, such as radium, polonium, etc. 41 of these have a half life of greater than one hour. Radioactive synthetic half-life ≥ 1.0 hour). Includes most useful radiotracers. 662 989
curium, Cm, named after Pierre and Marie Curie, scientists who separated out the first radioactive elements (1944), as its lighter analog gadolinium was named after Johan Gadolin. 97. berkelium, Bk, named after Berkeley, where the University of California, Berkeley is located (1949). 98.
The next group is the primordial radioactive nuclides. These have been measured to be radioactive, or decay products have been identified in natural samples (tellurium-128, barium-130). There are 35 of these (see these nuclides), of which 25 have half-lives longer than 10 13 years. With most of these 25, decay is difficult to observe and for ...
Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the environment, such as uranium, thorium and potassium and any of their decay products, such as radium and radon. [1]
Non-mononuclidic elements are marked with an asterisk, and the long-lived primordial radioisotope given.In two cases (indium and rhenium), the most abundant naturally occurring isotope is the mildly radioactive one, and in the case of europium, nearly half of it is.