Magnets and magnetic forces — Science, 7–10 years
Magnets can pull some materials without touching them, and their poles affect how they interact.
The idea
A magnet can pull certain materials, such as iron and steel, even when there is a small gap. Every magnet has two ends called poles. Unlike poles attract each other, while like poles push apart; the invisible region where this happens is a magnetic field.
Why it matters
People first needed to explain why some stones pulled iron and why a compass could point in one direction. The problem was invisible action at a distance: there was no obvious string or touch. Magnetism gives a useful explanation and helps us predict attraction and repulsion.
A worked example
Place a bar magnet on a table with its north pole facing another magnet’s north pole. Move the magnets close together: they push apart. Turn the second magnet around so its south pole faces north. Move them close again: this time they pull together.
A common trap
A common guess is that every metal must be attracted to a magnet. That is understandable because many familiar magnetic objects look metallic. But aluminium foil, copper wire and a coin may not be pulled strongly; magnetism depends on the material, not simply on being shiny or hard.
Where it is used
A compass uses a small magnet to line up with Earth’s magnetic field and help with direction. Magnets hold notes on a fridge, lift some scrap metal and help electric motors turn. These uses work only when the materials and magnetic poles interact in the right way.
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