electric_charge

plasmapy.particles.atomic.electric_charge(particle: Particle) → Quantity

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

Parameters:

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

Returns:

The electric charge in coulombs.

Return type:

Quantity

Raises:

• 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.

• ParticleWarning – If the input represents an ion with a charge number that is below -3.

Notes

This function supports two formats for charge number information.

The first format is a string that has information for the element or isotope at the beginning, a space in between, and the charge number 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.

Examples

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