"stable" nuclides. In this definition, "stable" means a nuclide that has never been observed to decay against the natural background. Thus, these elements have half-lives too long to be measured by any means, direct or indirect.

Stable isotopes:
* 1 element (tin) has 10 stable isotopes
* 5 elements have 7 stable isotopes apiece
* 7 elements have 6 stable isotopes apiece
* 11 elements have 5 stable isotopes apiece
* 9 elements have 4 stable isotopes apiece
* 5 elements have 3 stable