Specific charge

The specific charge of a subatomic particle, nucleus or isotope is the ratio of its charge to its mass.

In other words, how much charge it has for every unit of mass.

Calculating specific charge

We can use this formula to calculate the specific charge of a particle, nucleus or isotope:

\text{Specific charge} = \frac{\text{Charge}}{\text{Mass}}

Sometimes, we represent specific charge as just \frac Qm because of its formula.

Where:

Because we are dividing charge (C) by mass (kg), our units are C\div kg\rightarrow C\,kg^{-1}

If you want the details of the different subatomic particles and their specific charges, see:

Otherwise, I’ve written a summary table below!

Particle	Charge (Q)	Mass (m)	Specific charge (\frac Qm)
proton	+1.6\times10^{-19}C	1.67\times10^{-27}kg	+9.58\times10^{7}C/kg
neutron	0	1.675\times10^{-27}kg	0
electron	-1.6\times10^{-19}C	9.11\times10^{-31}kg	-1.76\times10^{11}C/kg