# Definition:Proton

## Proton

A proton is an elementary particle which contains a single unit of positive elementary electric charge.

### Charge

The electric charge on the proton is $1.60217 \, 6634 \times 10^{−19}$ coulombs.

That is, a positive charge whose magnitude is the value of the elementary charge.

### Mass

The mass of the proton is approximately $1.67262 \, 19236 \, 9(51) \times 10^{-27}$ kilograms.

That is, approximately $1837$ times the mass of the electron.

The radius of the proton is approximately $0.8414(19) \times 10^{-15}$ metres.