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What is Electricity?

What Is Electricity?
No one knows exactly what electricity is. It has been a mystery for thousands of years. It has no weight but it can lift and move thousands of tonnes. It has no shape, but it is everywhere. We cannot see it, but it produces light. We do know however, what electricity does and how to harness it.

The Atom
To learn more about electricity, we must know more about the atom. Everything we know is made up of atoms. These atoms are so small that it takes millions of them to form a speck of dust.

The elements of an atom are:

A positively charged "proton"
A negatively charged "electron"
The neutral "neuron"

The negative charge of the electron is equal to the magnitude of the positive charge of the proton. These elements are arranged the same generally in all atoms. The protons and the neurons always form a closely packed group called the nucleus, which has a positive charge due to the protons. Outside the nucleus and a relatively large distance away from it, are the electrons, whose number is equal to the number of protons in the nucleus. If the atom is undisturbed and no electrons are removed from the space around the nucleus, the atom remains electrically neutral. If, on the other hand, one or more electrons have been removed, the remaining positively charged structure is called a positive ion. A negative ion is an atom that has gained one or more extra electrons.

A conductor is a material - solid, liquid or gas, within which there are "free" electrons. These electrons will move when a force is exerted on them. The free charge in a metallic conductor is negative electrons.

The movement of these free electrons in a metallic conductor creates an electric current.

Some materials are better conductors than others are. Good conductors have a free electron orbiting the others. Free electrons link up with others to create a flow.

Any particular electron does not move from one end of a conductor to the other. The movement of electrons may be compared to a shunting train engine bumping a standing string of railway trucks on a railway track. When the engine bumps one end of the string, each truck progressively bumps the next.

If a free electron from a source of energy is forced into an atom at one end, it tends to upset the balance between electrons and protons of the first atom. This forces the first atom to release an atom into an adjacent atom, and so on. This forcing and releasing of electrons in one direction within the conductor is called dynamic electricity or current in motion.

The greater the numbers of free electrons in a conductor, the stronger the current that can flow through it. Switching on an appliance allows the current to flow through its element or motor.

Every billionth of a second, 3 billion free electrons flow through the filament of a light bulb when it is switched on.

Free electrons slow-down when they bump into other atoms of the conductor. This slow-down in their movement is called resistance.

To transmit electricity throughout the state of Victoria, conductors with low resistance are used to provide the easiest path possible for free electrons as they shunt each other from the power station to the point of electricity use.