# Definition:Electric Charge

## Definition

Electric charge is a physical quantity of matter which causes it to experience a force when near other electrically charged matter.

It is a scalar quantity.

### Quantum

Electric charge has been demonstrated to be quantized.

The quantum of electric charge is the elementary charge $\E$:

$\E = 1.60217 \, 6634 \times 10^{−19}$ coulombs exactly.

This is so small that to all practical purposes in everyday measurement of electricity, it can be treated as though it were continuous.

### Dimension

The dimension of measurement of electric charge is $\mathsf {I T}$.

### Units

The SI unit of electric charge is the coulomb $\mathrm C$.

## Sign

The sign of an electric charge can be one of $2$ types:

### Positive Electric Charge

A positive electric charge is an electric charge which is of the same sign as the electric charge on a proton.

When it is necessary to assign a value to a positive electric charge, a $+$ (plus) sign is used, and the value assigned is a positive number.

### Negative Electric Charge

A negative electric charge is an electric charge which is of the same sign as the electric charge on an electron.

When it is necessary to assign a value to a negative electric charge, a $-$ (minus) sign is used, and the value assigned is a negative number.

## Neutral

A body which has no electric charge on it is described as (electrically) neutral.