Electricity
When we refer to electricity, what we usually mean is electric current, which is the flow of electric charge.
Where does Electricity come from?
Electricity that occurs naturally....
Static Electricity
Static charge can build up when two insulating materials are rubbed together, such as a plastic comb moving through hair.
Friction between the materials causes tiny particles to be transferred from one material to the other, building up an electric charge.
The balloon has gained more negative charge and so attracts (and 'sticks') to the wall. If two balloons were charged, they would repel (push away) from each other.
Electric Animals
All living animals produce small amounts of electricity. Tiny electric signals spread through your heart muscles to trigger a heartbeat. Many creatures use this electric pulse to help them hunt and kill other animals.
For example, a shark has 1,000 electricity sensing pits around it's head, which it then uses to pick up tiny electrical signals from the muscles of fish.
An electric eel has special cells in their body that produces strong electric discharges. Electric eels can use these to electrocute other fish (or to give humans a nasty shock!)
...Or it can be made from other sources...
There are two types of electrical current that we can use to power appliances.
Electrical Circuits
Current electricity is the flow of electrical charge though materials.
Every complete circuit must have a power supply. The power supply could be the mains (AC), or it could be a battery (DC).
For a circuit to be complete, there must be wires connected to both the positive and negative ends of the power supply.
Electricity can only flow around a complete circuit that has no gaps.
Electric Symbols
This is a diagram of a circuit , using the different elements.
Insulators and Conductors
Some materials allow electricity to flow through it, they are called conductors.
Most materials do not allow electricity to flow through it, they are called insulators
Wires contain copper (a type of metal) which allow the electricity to flow. The plastic around the outside is an insulator, which is why you do not get an electric shock.
This game allows you to spot the hazards with electricity around the home.