Question: How do magnets stick to metal? (I'm in junior Infants)

Ciarán O'Brien answered on 17 Nov 2014:

Hey, I hope I’ve made this answer easy to follow. Sorry if it’s complicated, but magnets are actually really really complicated too!

Magnetism is a really strange thing, and nobody completely understands how it works yet.

First things first though, magnets won’t stick to all metals! The best magnets and the metals that stick to them best are made of iron, or contain iron.

We know that magnets generate a sort of force field. You can’t see it, but if you sprinkle iron filings around a magnet you can see where it is and what shape it is. You can see that the force field travels in a sort of bubble shape from one pole of the magnet to the other (we call them north and south poles because our planet is also a magnet, and when the point of a compass points north it’s because it’s trying to stick to the earth!). Here’s a short video that shows how iron filings can point out where the magnetic field on a magnet is: https://www.youtube.com/watch?v=8llkHQtaOlg

But what generates that force field and how does it work? That’s actually a very complicated question and the answer is pretty complicated too. So everything is made up of atoms, right? they’re the smallest piece of a metal you can get that still behaves like a bigger chunk of the metal. Atoms are made of even smaller things called protons and electrons. The electrons move about around the protons a bit like how planets orbit the sun.

Scientists discovered that when these electrons move, they generate a tiny magnetic field. The more electrons that move, the stronger the field. We don’t really know how they generate the force field. Well, I don’t know. If you could find someone who knows quantum physics they might be able to tell you, but that stuff is very hard to learn!

It turns out that any metal that sticks to a magnet is also a magnet! Well, actually it’s billions of tiny magnets, as each atom making it up is a magnet. they’re all pointing different ways though and that normally cancels the force field. But when you bring another magnet close to it, all the tiny magnets in the metal realign!

You know how one pole of a magnet is attracted to the other pole of another magnet, and if you try and brin two of the same pole together they force eachother apart? That’s what’s happening when you bring a magnet close to a metal, all the tiny magnet atoms turn about so that the opposite pole is facing the magnet. and opposite poles attract each other, so the metal sticks to the magnet. When you take the magnet away all the tiny magnets turn back to their original directions.

Sorry I can’t tell you about all the details, but I don’t understand quantum physics very well!