Magnets
Physics · Key Stage 1 · The School
Testing, not guessing
Take a magnet round the room and try it on everything: a paperclip, a coin, a spoon, a pencil, a plastic ruler, a can. Sort into 'sticks' and 'does not stick' before you try to explain anything. The results will surprise you.
Not all metals
Here is the surprise. A steel paperclip sticks; an aluminium can does not; many coins do not. So 'metal' is not the answer — only iron, steel, nickel and cobalt are magnetic. Anything that is not made of those will not stick, however metallic it looks.
Two ends, two behaviours
Every magnet has a NORTH and a SOUTH pole. Put two norths together and they push apart — they REPEL. Put a north and a south together and they snap together — they ATTRACT. Feel the invisible push; it is one of the few forces you can feel without touching.
Line up a steel paperclip, a 2p coin, an aluminium drinks can, a steel spoon and a gold-coloured ring. Predict which will stick, then test each one. The paperclip and spoon stick; the can does not; most coins do not. So 'metal' was the wrong prediction rule. Sort your results again into 'iron or steel' and 'other metal' and the pattern comes out exactly right — which is how a rule gets corrected.