plasmapy.particles.atomic.common_isotopes(argument: str | Integral | None = None, most_common_only: bool = False) list[str][source]

Return a list of isotopes of an element with an isotopic abundances greater than zero, or if no input is provided, a list of all such isotopes for every element.

  • argument (atom-like, optional) – A string or integer representing an atomic number or element, or a string representing an isotope.

  • most_common_only (bool) – If set to True, return only the most common isotope.


List of all isotopes of an element with isotopic abundances greater than zero, sorted from most abundant to least abundant. If no isotopes have isotopic abundances greater than zero, this function will return an empty list. If no arguments are provided, then a list of all common isotopes of all elements will be provided that is sorted first by low to high atomic number and second by most abundant to least abundant isotope.

Return type:

list of str



The isotopic abundances are based on the terrestrial environment and may not be appropriate for space and astrophysical applications.

See also


Returns a list of isotopes that have been discovered.


Returns isotopes that are stable against radioactive decay.


Returns the relative isotopic abundance.


>>> common_isotopes('H')
['H-1', 'D']
>>> common_isotopes(44)
['Ru-102', 'Ru-104', 'Ru-101', 'Ru-99', 'Ru-100', 'Ru-96', 'Ru-98']
>>> common_isotopes('beryllium 2+')
>>> common_isotopes('Fe')
['Fe-56', 'Fe-54', 'Fe-57', 'Fe-58']
>>> common_isotopes('Fe', most_common_only=True)
>>> common_isotopes()[0:7]
['H-1', 'D', 'He-4', 'He-3', 'Li-7', 'Li-6', 'Be-9']