How do magnets work?

The longer answer

Magnets only pull on some materials. Iron and steel stick, and so do a few other metals like nickel. Wood, plastic, paper and most coins do not, which is why a magnet slides right off a wooden door.

The two ends of a magnet are called the north pole and the south pole. Put a north next to a south and they snap together. Put two norths, or two souths, together and you can feel them push each other away.

The pull is strongest close to the magnet and fades as you move away. That is why a paper clip jumps onto a magnet only once you bring them near each other.

Three things to know

• The Earth is a giant magnet. Hot iron deep inside the Earth turns the whole planet into a magnet, and a compass needle swings round to point north along it.
• Fridge magnets stay up because the door has iron in it. A fridge door is made of steel, and steel is mostly iron, so a magnet holds on to it all day.
• The strongest magnets can lift a whole car. In a scrapyard, a huge magnet on a crane grabs old cars by their iron bodies and lets go when it is switched off.

Try it at home: a magnet hunt

1. Take a fridge magnet on a walk around your home.
2. Before you touch it to something, guess: will it stick?
3. Test spoons, keys, doors, coins, foil and toys.
4. Sort everything into two piles: sticks and does not stick. What do the sticky things have in common?

Keep magnets away from phones, tablets and bank cards, and keep small magnets away from little ones who might swallow them.