plasmapy.particles.common_isotopes(argument: Union[str, numbers.Integral] = None, most_common_only: bool = False) → List[str]

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 (int or str, 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.

isotopes_list – 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 by atomic number, with entries for each element sorted from most abundant to least abundant.

Return type:

list of str or empty list

  • 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.


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

See also

known_isotopes : returns a list of isotopes that
have been discovered.
stable_isotopes : returns isotopes that are stable
against radioactive decay.
isotopic_abundance : returns the relative isotopic


>>> 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']