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Magnetism is one of the few invisible forces a child can feel directly. These eight experiments use nothing more than a few magnets, paper clips, and kitchen items, and each one isolates a principle — attraction, repulsion, field shape, induced magnetism — that explains why a fridge magnet works and why a compass points north. The theory behind magnetism is covered in what magnetism is; these are the hands-on demonstrations that make the theory stick.
What you need
One or two bar magnets or refrigerator magnets, a handful of paper clips, a sewing needle, a cork or small piece of foam, a shallow dish of water, a sheet of paper, iron filings or steel wool fibres, a clear plastic cup, and a few coins. Nothing on this list is unusual, and none of it is consumed in the experiments, so the same set can be reused.
Experiment 1: The invisible reach
Place a paper clip on the table and move a magnet toward it slowly, without touching it. Note the distance at which the clip jumps. Then try the same with a plastic pen cap, a coin, and a wooden block. Only the clip moves.
What is happening: A magnetic field extends through space and exerts force on ferromagnetic materials — iron, nickel, cobalt, and some alloys. It does not affect most other materials, which is why the coin and the wood stay put. The distance at which the clip jumps is a rough measure of field strength at that point.
Experiment 2: The field map
Place a bar magnet under a sheet of paper. Sprinkle iron filings lightly over the paper and tap the paper gently. The filings align into curved lines running from one pole to the other.
What is happening: Each iron filing becomes a tiny compass needle, aligning with the local direction of the magnetic field. The pattern you see is a two-dimensional slice of the field lines that surround every magnet. The lines are densest near the poles, which is where the field is strongest. Do not use strong neodymium magnets for this — the filings stick permanently and the pattern is lost.
Experiment 3: The floating compass
Stroke a sewing needle in one direction along the north pole of a bar magnet, about fifty times. Push the needle through a small piece of cork and float it in a shallow dish of water. It will align north-south.
What is happening: The needle is made of steel, which is ferromagnetic. The stroking process aligns magnetic domains inside the steel, turning the needle into a weak permanent magnet. Earth’s magnetic field exerts a torque on this magnet, and because the cork is free to rotate in water, the needle aligns with the field. The end that points north is the needle’s north-seeking pole.
Experiment 4: Like repels, unlike attracts
Mark the poles of two bar magnets if they are not already marked. Bring two north poles together — they push apart. Bring a north and a south together — they pull. The force is equal in both cases.
What is happening: Magnetic poles follow a rule: like poles repel, opposite poles attract. The force decreases rapidly with distance, roughly as the inverse cube of the separation. This is why the push or pull is gentle at arm’s length but firm when the magnets are close.
Experiment 5: The chain
Touch a paper clip to the north pole of a magnet. Touch a second clip to the first. Touch a third to the second. The chain holds, but if you remove the magnet, the clips at the far end fall away.
What is happening: The first clip becomes magnetised by induction — the magnet’s field aligns domains inside the clip, turning it into a temporary magnet. That clip then magnetises the next one, and so on. But the induced magnetism is weak, and each link in the chain is farther from the original field source. Remove the source, and the domains randomise. The clips at the far end lose their alignment first.
Experiment 6: The magnetic shield
Place a paper clip on the table and confirm that a nearby magnet attracts it. Now slide a sheet of aluminium foil between the magnet and the clip. The clip still jumps. Slide a sheet of iron — a steel ruler, or a stack of steel paper clips — between them. The attraction weakens or stops.
What is happening: Magnetic fields pass through most materials, including aluminium, plastic, and wood, essentially unchanged. But ferromagnetic materials provide a lower-reluctance path for the field lines, drawing them away from the paper clip. This is why a refrigerator door — steel — does not let the magnet’s field reach the contents inside, while a plastic container does.
Experiment 7: The water test
Drop a paper clip into a glass of water. Hold a magnet against the outside of the glass, near the clip. The clip moves toward the magnet, even through the water and the glass.
What is happening: Magnetic fields are not blocked by water or glass. This is different from electric fields, which are strongly affected by conductive materials. The demonstration shows that magnetic force acts at a distance through most everyday substances, which is why a compass works inside a wooden ship and why MRI scanners can see inside a human body.
Experiment 8: The strength test
Place a paper clip on the table. Count how many sheets of paper you can stack between the magnet and the clip before the attraction fails. Repeat with cardboard, plastic, and a thin steel sheet. Record the number for each material.
What is happening: The number of sheets is a rough measure of how much the material weakens the field. Paper and plastic weaken it very little. Steel weakens it dramatically. This is the same principle used in magnetic shielding for sensitive electronics, where a steel or mu-metal enclosure redirects unwanted magnetic fields around the device rather than through it.
How to keep a record
Each experiment produces one observation and one principle. The record does not need to be elaborate. A simple table with three columns — experiment, what we saw, what it means — is enough to turn the activity into a homeschool science entry. For advice on keeping a science journal that evaluators take seriously, see how to keep a science journal.
