plasmapy.particles.electric_charge(particle: plasmapy.particles.particle_class.Particle) → astropy.units.quantity.Quantity

Return the electric charge (in coulombs) of a particle.


particle (str) – String representing an element or isotope followed by integer charge information.


charge – The electric charge in coulombs.

Return type:


  • InvalidParticleError – If the argument does not correspond to a valid particle or contradictory information is provided.
  • ChargeError – If charge information for the particle is not available.
  • AtomicWarning – If the input represents an ion with an integer charge that is below -3.


This function supports two formats for integer charge information.

The first format is a string that has information for the element or isotope at the beginning, a space in between, and the integer charge information in the form of an integer followed by a plus or minus sign, or a plus or minus sign followed by an integer.

The second format is a string containing element information at the beginning, following by one or more plus or minus signs.

This function returns -1.6021766208e-19 C for electrons and 1.6021766208e-19 C for positrons.


>>> electric_charge('p+')
<<class 'astropy.constants.codata...'> name='Electron charge' ...>
>>> electric_charge('H-')
<Quantity -1.60217662e-19 C>