Electric Charge

Electric Charge

Charge tells us why some objects attract or repel electrically.

Two positive charges repel.

Two negative charges repel.

Positive and negative attract.

Electric Charge

Electric charge is a physical property of matter responsible for electric forces and interactions.

There are two kinds of charge:

positive charge

and

negative charge

Like charges repel each other:

positive + positive → repel

negative + negative → repel

Unlike charges attract:

positive + negative → attract

The SI unit of charge is the coulomb (C).

Charge in Atoms

Atoms contain:

positively charged protons; negatively charged electrons; * electrically neutral neutrons.

An atom is neutral when the total positive and negative charges balance.

If an object gains electrons, it becomes negatively charged.

If it loses electrons, it becomes positively charged.

Conservation of Charge

Electric charge is conserved.

Charge is not created or destroyed in ordinary charging processes. It is transferred from one body to another.

Quantisation

Charge occurs in discrete amounts related to the elementary charge:

**e = 1.6 × 10⁻¹⁹ C**

Charge can be written as:

**Q = ne**

where `n` is an integer.

Electric Charge — Advanced

Electric charge is a conserved and quantised property.

At the atomic level, ordinary electrostatic charging usually results from transfer or redistribution of electrons rather than movement of protons between objects.