What do magnets pick up?
A farmer sticks his work list to the wall of a tractor with a magnet. A magnet attracts, or pulls, some things without anyone pushing or pulling them by hand. A magnet attracts things made of iron. Steel is made from iron, so it is attracted too. A paper clip, a nail, a steel pin and many food tins are attracted. Wood, plastic, paper, cloth, glass and rubber are not. Not every metal is attracted: aluminium foil is a metal, but a magnet does not pick it up. Nickel and cobalt are attracted too. So we test objects instead of guessing, and sort them into attracted and not attracted. Cows eat grass and may swallow small bits of iron. A farmer, with a vet’s help, can give a cow a large, smooth magnet. It stays in the cow’s stomach and holds the iron bits together, so they cannot hurt the cow. Only vets and farmers do this. Every magnet has two ends called poles, where it pulls strongest.
| Object | Made of | Attracted? |
|---|---|---|
| paper clip | steel | yes |
| wooden pencil | wood | no |
| food tin | steel | yes |
| aluminium foil | aluminium | no |
Magnet test, with a grown-up. Collect ten objects from home and school, for example a paper clip, a nail, a pencil, a rubber, a plastic comb, a steel screw, a piece of cloth, a glass, some aluminium foil and a food tin. Predict first with a tick or a cross. Then touch each one with a large school magnet and write the result in a table: Object, My prediction, Attracted? Finish the class rule: A magnet attracts things made of … . Think of another way to keep iron bits out of a cow’s food, for example sweeping the field with a magnet on a long handle. Keep magnets away from phones, cards and screens, and never put a magnet near your mouth. Only a grown-up gives out the magnets.