What Is a Magnet?
A magnet is an object that pulls certain materials towards it without touching them. This pull is called magnetic force, or attraction. Magnets come in many shapes: bar magnets, horseshoe (U-shaped) magnets, ring magnets, disc magnets and the flexible magnets on fridge doors. Whatever the shape, every magnet has two poles, a north-seeking pole (N) and a south-seeking pole (S), and the magnetic force is strongest at the poles.
Children can explore all of this in the lab above. Start by dragging the magnet over the objects on the table, then predict before you test: will the aluminium can jump onto the magnet? Will the food can?
Magnetic and Non-Magnetic Materials
Materials that are attracted to a magnet are called magnetic materials. There are only four that children need to know: iron, steel, nickel and cobalt. Steel is mostly iron, which is why so many everyday magnetic objects, such as paper clips, nails, screws and food cans, are made of steel. Every other material is non-magnetic, and that includes many metals.
| Object | Made of | Attracted to a magnet? |
|---|
The biggest surprise for most children is that not all metals are magnetic. Aluminium, copper, gold, silver and brass are all metals, but a magnet does not attract them. Recycling centres use this difference: a large magnet lifts the steel cans out of a pile of mixed cans, leaving the aluminium drink cans behind. Another surprise is that some stainless steel is hardly magnetic at all, so a stainless-steel spoon or sink may not hold a magnet. That is why this lab uses steel screws and paper clips rather than spoons.
Poles: Attract and Repel
When two magnets are brought together, the poles that face each other decide what happens. Like poles repel: north and north, or south and south, push each other away. Unlike poles attract: north and south pull together. In the two-magnet lab, turn one magnet round and feel the difference. Repulsion is also the only sure test of whether something is a magnet: a magnet attracts a plain iron nail at either end, but it can only repel another magnet.
A bar magnet hung freely from a thread turns until its north-seeking pole points north. A compass needle is simply a small, light magnet that can spin, which is how people have found their way for hundreds of years.
Magnetic Force Without Touching
Magnetic force can act across a gap and through materials that are not magnetic, such as paper, plastic, thin wood, glass and even water. A fridge magnet holds a drawing because the force passes through the paper to the steel door. The force gets weaker as the distance grows, so in the “through a material” test, a stack of paper still lets the clip be attracted, but a few sheets of thick wood or glass put the clip too far away.
How Strong Is a Magnet?
A fair way to compare magnets is to count how many identical paper clips each one can hold in a chain from one pole. Change only the magnet, use the same kind of paper clips, and hang them from the same place each time. The size of a magnet does not tell you its strength: a small magnet can be stronger than a big one. In the strength test, also try hanging clips from the middle of the bar magnet. Almost nothing sticks there, because the force is strongest at the poles.
Making a Magnet
The stroke method. Stroke an iron nail or a steel needle from one end to the other with one pole of a magnet, about 20 to 30 times, always in the same direction, lifting the magnet well clear of the nail between strokes. Inside the iron are many tiny magnetic regions pointing every which way; stroking lines them up so they all point the same way, and the nail becomes a weak magnet. Stroking back and forth in both directions muddles them up again, which is why the lab takes strength away for a stroke in the wrong direction. Iron loses this magnetism quite quickly, especially if it is dropped or heated; steel keeps it longer.
The electrical method. When electricity flows through a coil of insulated wire wound round an iron nail, the nail becomes an electromagnet. It is stronger with more turns of wire and with more cells (more electric current), and most of its magnetism disappears the moment the switch is opened. That is what makes electromagnets so useful: they can be switched on and off. This part goes beyond the P3 topic and is a good extension for older children who are learning about circuits.
Uses of Magnets
- Fridge door seals and the magnetic catches on cupboards keep doors shut.
- Compasses help people find north when hiking, sailing or flying.
- Recycling plants separate steel cans from aluminium cans with large magnets.
- Electromagnets on cranes lift scrap iron and steel, then drop it when switched off.
- Loudspeakers, earphones, electric motors and electric bells all contain magnets.
- Magnetic toys, pencil cases, name badges and whiteboard magnets use small permanent magnets.
- Some fast trains float above the track using powerful magnets (maglev).
Common Misconceptions
- “All metals stick to magnets.” Only iron, steel, nickel and cobalt do. Aluminium, copper, gold and silver do not.
- “Bigger magnets are always stronger.” Strength depends on the material and how it was made, not just the size.
- “A magnet can repel a paper clip.” A magnet only attracts magnetic materials. Only another magnet can be repelled.
- “Magnets need to touch to work.” Magnetic force acts across a gap and through non-magnetic materials.
- “The force is the same all along a magnet.” It is strongest at the poles and weakest in the middle.
Safety with Magnets
Small, strong magnets are dangerous if swallowed, because two magnets inside the body can pull together through the intestines. Keep them away from babies and toddlers. Keep strong magnets away from bank cards, older computers and pacemakers. Never connect an electromagnet to mains electricity: use cells only, and switch off between tests because the wire can get warm.
How to Use This Page
- Test the objects. Drag the magnet near each object, or tap an object, and watch the two results lists fill up.
- Try two magnets. Drag the right-hand magnet in, turn either magnet round and compare.
- Test force and strength. Add sheets of a material between the magnet and the clip, and hang clips from different magnets and places.
- Make a magnet by stroking the nail, then build an electromagnet.
- Choose a level and a quiz: sorting objects, attract or repel, and true or false. Each round earns up to three stars, kept on this device.
- Print a worksheet with a sorting table, pole pairs, true or false statements and an answer page.
Links to the Primary Science Syllabus
Magnets are part of the “Interactions” theme in Singapore lower primary science, usually taught in Primary 3. Children learn the characteristics of magnets (they attract magnetic materials, they have two poles, like poles repel and unlike poles attract, a freely hanging magnet points north and south), which materials are magnetic, how to make a magnet by the stroke method and by the electrical method, and everyday uses of magnets. Questions often ask children to plan a fair test of magnet strength or to explain why an object made of metal is not attracted.
Tips for Parents and Teachers
- Predict first. Before testing each object, ask: “Is it magnetic? What is it made of?”
- Use real cans. Hold a fridge magnet against a food can and a drink can from the kitchen. The difference is memorable.
- Insist on the material. A good answer names the material: “The ring is not attracted because it is made of gold, which is not a magnetic material.”
- Make it a fair test. When comparing magnets, ask what must stay the same: the kind of clip, where they hang, how they are added.
Nothing to Install, Nothing Uploaded
The magnet lab runs entirely in your browser on any phone, tablet or computer, with no account and no download. Your level, quiz and stars are kept only in your own browser; answers are never sent to us.
Frequently Asked Questions
No. Only a few metals are magnetic materials: iron, steel (which is mostly iron), nickel and cobalt. Many common metals, such as aluminium, copper, gold, silver and brass, are not attracted to a magnet at all. An aluminium drink can and a copper wire do not stick to a magnet, but a steel food can does.
Every magnet has a north (N) pole and a south (S) pole. When two magnets are brought together, two north poles or two south poles push each other away (repel), and a north pole and a south pole pull towards each other (attract). Scientists describe this with magnetic fields; at primary level it is enough to remember: like poles repel, unlike poles attract.
Stroke an iron nail or a steel needle about 30 times with one pole of a magnet, always in the same direction, lifting the magnet high above the nail before each new stroke. The nail becomes a weak magnet that can pick up a paper clip. You can also wind insulated wire around an iron nail and connect it to a battery to make an electromagnet.
Yes. Magnetic force can act through non-magnetic materials such as paper, plastic, thin wood, glass and water. That is why a fridge magnet can hold a sheet of paper. The force gets weaker with distance, so if the layers are too thick, the magnet is too far away and the object is no longer attracted.