We’re surrounded by electrically powered devices these days. From our lights, to our kettles, and of course our phones!
Electricity flows through copper or aluminium wire to power or charge all of these things. That’s because metals are generally good electrical conductors
That’s one of the reasons that you should never touch exposed electrical wires!
Metals have lots of electrons, and some of them are free to move through the metal, so when they’re connected in a circuit, the electrons can easily flow. This flow of electric charge is called a current.
Some metals are much better at conducting electricity than others.
Copper is a very good conductor.
And so is aluminium.
Whereas stainless steel conducts, but not quite as well.
Other materials can also conduct electricity, as long as they let the charge flow freely through them.
Like the graphite in a pencil.
Or this salty water.
Now, the outside of electric wires are usually covered in plastic because it’s a very poor conductor. It hardly conducts any electricity at all, so we can say it’s an electrical insulator.
Inside the plastic, all the electrons are tightly bound to the atoms, so the charges cannot move very far, and no current can flow.
And you can touch the wire and the outer casing of the electrical items without worrying about getting a shock.
Other insulators, which don’t allow electric current to flow through them, include wood and glass.
Although I can see why they chose plastic to wrap electrical wires. I wouldn’t fancy using a phone charger made of glass!
