Summary Table For Numbers of Each Class of Nuclides
This is a summary table from List of nuclides. Note that numbers are not exact, and may change slightly in the future, as nuclides are observed to be radioactive, or new half-lives are determined to some precision. Note that only the 254 have any claim to stability, but that only 90 nuclides from the first 40 elements are theoretically stable to any process but proton decay.
| Type of nuclide by stability class. | Number of nuclides in class (exact number may change). | Running total of nuclides in all classes to this point. | Notes on running total. |
|---|---|---|---|
| Theoretically stable to all but proton decay. | 90 | 90 | Includes first 40 elements. Proton decay yet to be observed. |
| Energetically unstable to one or more known decay modes, but no decay yet seen. Considered stable until radioactivity confirmed. | 164 | 254 | Spontaneous fission possible for "stable" nuclides > niobium-93. Other mechanisms possible for heavier nuclides. Total is the classically stable nuclides |
| Radioactive primordial nuclides. | 34 | 288 | Total primordials include Bi, U, Th, Pu, plus all stable nuclides. |
| Radioactive nonprimordial, but naturally occurring on Earth. | ~ 51 | ~ 339 | Cosmogenic nuclides from cosmic rays; daughters of radioactive primordials such as francium, etc. |
Read more about this topic: Stable Isotope
Famous quotes containing the words summary, table, numbers and/or class:
“Product of a myriad various minds and contending tongues, compact of obscure and minute association, a language has its own abundant and often recondite laws, in the habitual and summary recognition of which scholarship consists.”
—Walter Pater (1839–1894)
“Thou preparest a table before me in the presence of mine enemies; thou anointest my head with oil; my cup runneth over.”
—Bible: Hebrew Psalms, 23:5.
“I had but three chairs in my house; one for solitude, two for friendship; three for society. When visitors came in larger and unexpected numbers there was but the third chair for them all, but they generally economized the room by standing up.”
—Henry David Thoreau (1817–1862)
“There is a certain class of unbelievers who sometimes ask me such questions as, if I think that I can live on vegetable food alone; and to strike at the root of the matter at once,—for the root is faith,—I am accustomed to answer such, that I can live on board nails. If they cannot understand that, they cannot understand much that I have to say.”
—Henry David Thoreau (1817–1862)