Magnets
Physics · Key Stage 1 · The School
Testing, not guessing
Take a magnet round the room. Try it on everything. A paperclip. A coin. A spoon. A pencil. A plastic ruler. A can. Sort them into two piles: sticks, and does not stick. Do that 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 either. So metal is not the answer. Only iron, steel, nickel and cobalt are magnetic. Anything not made of those will not stick, however metallic it looks.
Two ends, two behaviours
Every magnet has two ends. There is a NORTH pole 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 that invisible push. It is one of the few forces you can feel without touching anything.
Line up five things. A steel paperclip. A 2p coin made after 1992. An aluminium drinks can. A steel spoon. A gold-coloured ring. Predict which ones will stick. Then test each one. The paperclip and the spoon stick. The 2p coin sticks too. Under its copper coat it is steel. The can does not. So metal was the wrong rule for predicting. Now sort your results again, into iron-or-steel and other-metal. The pattern comes out exactly right. That is how a rule gets corrected.