# Physics: static electricity, electric charges and law of charges.

## What is electricity?

The is a form of energy that occurs when electrons flows through a conductor.

### Areas Covered

• Definition of static electricity
• Nature of atoms of static electricity
• Electricity charges
• Law of charges
• Conductor and insulator

### Definition of static electricity

Static electricity is that produces by friction between two materials. For example, when evolution is rubbed with force or when rod is rubbed with silk.

### Nature of atoms

An atom consists of a central core, the core is called the nucleus. This is surrounded by electrons moving at different energy levels called ORBIT. The nucleus contains two kinds of particles called the protons and neutrons. The electrons has a positive charge , while the protons has positive charge.

### Electric charge

Positive charge is obtained when a glass rod is rubbed with silk or cellulose acetate with silk. Negative charge is obtained when an ebonite rod is rubbed with fur or polythene with fur.

This two rods with positive and negative electrification attracts each other when brought close.

### Law of charges

This refers to the fact that "Like or similar charges repel each other, unlike or opposite charges attracts each other" in essence.

#### Conductor and insulator

In static electricity, substances are classified according to the degree of resistance they offer to the passage of electrons through them. There are two groups: conductor and insulator.

A Conductor has small resistance to current flow, so current flows easily. For example: Metals and living thing.

An Insulator has large resistance to current flow and therefore does not flow easily. For example: glass, wood, mica etc.