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)
“When I think of our lands I think of the house
And the table that holds a platter of pears,
Vermilion smeared over green, arranged for show.”
—Wallace Stevens (1879–1955)
“Old age equalizes—we are aware that what is happening to us has happened to untold numbers from the beginning of time. When we are young we act as if we were the first young people in the world.”
—Eric Hoffer (1902–1983)
“You must drop all your democracy. You must not believe in “the people.” One class is no better than another. It must be a case of Wisdom, or Truth. Let the working classes be working classes. That is the truth. There must be an aristocracy of people who have wisdom, and there must be a Ruler: a Kaiser: no Presidents and democracies.”
—D.H. (David Herbert)