# stable_isotopes¶

plasmapy.atomic.stable_isotopes(argument: Union[str, numbers.Integral] = None, unstable: bool = False) → List[str]

Return a list of all stable isotopes of an element, or if no input is provided, a list of all such isotopes for every element.

Parameters
Returns

StableIsotopes – List of all stable isotopes of an element, sorted from lowest mass number. If an element has no stable isotopes, this function returns an empty list.

Return type

list of strings or empty list

Raises
• InvalidElementError – If the argument is a valid particle but not a valid element.

• InvalidParticleError – If the argument does not correspond to a valid particle.

• TypeError – If the argument is not a string or integer.

Notes

There are 254 isotopes for which no radioactive decay has been observed. It is possible that some isotopes will be discovered to be unstable but with extremely long half-lives. For example, bismuth-209 was recently discovered to have a half-life of about 1.9e19 years. However, such isotopes can be regarded as virtually stable for most applications.

known_isotopesreturns a list of isotopes that

have been discovered

common_isotopesreturns isotopes with non-zero

isotopic abundances

Examples

>>> stable_isotopes('H')
['H-1', 'D']
>>> stable_isotopes(44)
['Ru-96', 'Ru-98', 'Ru-99', 'Ru-100', 'Ru-101', 'Ru-102', 'Ru-104']
>>> stable_isotopes('beryllium')
['Be-9']
>>> stable_isotopes('Pb-209')
['Pb-204', 'Pb-206', 'Pb-207', 'Pb-208']
>>> stable_isotopes(118)
[]


Find unstable isotopes using the unstable keyword.

>>> stable_isotopes('U', unstable=True)[:5]  # only first five
['U-217', 'U-218', 'U-219', 'U-220', 'U-221']