Specific Charge
Specific charge is another title for the charge-mass ratio. This is a measure of the charge per unit mass and is simply worked out by worked out by dividing the charge of a particle by its mass.
You can think of it as a how much charge (in Coulombs) you get per kilogram of the ‘stuff’.
| Constituent | Charge (C) | Mass (kg) | Charge-Mass Ratio (C kg-1) or (C/kg) | |
|---|---|---|---|---|
| Proton | 1.6 x 10-19 | 1.673 x 10-27 | 1.6 x 10-19 ÷ 1.673 x 10-27 | 9.58 x 107 |
| Neutron | 0 | 1.675 x 10-27 | 0 ÷ 1.675 x 10-27 | 0 |
| Electron | (-) 1.6 x 10-19 | 9.1 x 10-31 | 1.6 x 10-19 ÷ 9.11 x 10-31 | (-) 1.76 x 1011 |
We can see that the electron has the highest charge-mass ratio and the neutron has the lowest.