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 given by:

\(\ds m_{\mathrm p}\)

\(\approx\)

\(\ds 1 \cdotp 67262 \, 19236 \, 9(51) \times 10^{-27}\)

kilograms

\(\quad\) This sequence is A070059 in the On-Line Encyclopedia of Integer Sequences (N. J. A. Sloane (Ed.), 2008).

\(\ds \)

\(\approx\)

\(\ds 1 \cdotp 67262 \, 19236 \, 9(51) \times 10^{-24}\)

grams

\(\quad\) This sequence is A070059 in the On-Line Encyclopedia of Integer Sequences (N. J. A. Sloane (Ed.), 2008).

\(\ds \)

\(\approx\)

\(\ds 1 \cdotp 00727 \, 64666 \, 21(53)\)

daltons

\(\quad\) This sequence is A003677 in the On-Line Encyclopedia of Integer Sequences (N. J. A. Sloane (Ed.), 2008).

Radius

The actual size of the proton is still unknown.

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

Also see

• Definition:Electron
• Definition:Neutron

• Results about protons can be found here.

Sources

• 1958: C.A. Coulson: Electricity (5th ed.) ... (previous) ... (next): Chapter $\text {I}$: Preliminary Survey: $\S 1$. Electrostatics
• 1990: I.S. Grant and W.R. Phillips: Electromagnetism (2nd ed.) ... (previous) ... (next): Chapter $1$: Force and energy in electrostatics: $1.1$ Electric Charge