Why Magnets Attract Some Materials

A strong magnet is brought near different objects: an iron nail, a steel paperclip, a copper coin, an aluminum can, and a plastic spoon. Some jump to the magnet, others don't move. Why?

• Not all metals are magnetic — only a few respond to a magnet.
• The difference is not weight, colour, or hardness — it's something inside the material.
• Our goal: find the hidden property that decides whether a material is attracted.

Before seeing the results, choose which items you think will be attracted to the magnet.

• Think about what you already know about magnets and metals.
• Don't worry about being wrong — this is a chance to test your intuition.

The iron nail and steel paperclip are strongly attracted and stick to the magnet. The copper coin, aluminum can, and plastic spoon are not attracted at all — they don't even feel a pull.

• Only iron, nickel, cobalt, and their alloys (like steel) are strongly attracted.
• Aluminum and copper are metals but are not attracted.
• Plastic, wood, glass, and most other common materials are not attracted either.

Inside a ferromagnetic material like iron, atoms group together into tiny regions called magnetic domains. Each domain acts like a tiny bar magnet with its own north and south pole. Normally, these domains point in random directions, so the material as a whole has no net magnetism. When a strong magnet comes near, the domains rotate and align with the external field, turning the whole object into a temporary magnet that is attracted. In non‑ferromagnetic materials, electrons are paired in a way that cancels their magnetic effect, or the atoms cannot form stable domains.

• Ferromagnetic materials contain magnetic domains — regions where atomic magnetic fields are aligned.
• Without an external magnet, domains point every which way and cancel each other out.
• A nearby magnet causes domains to line up, creating a net attraction.
• In non‑ferromagnetic materials, no such alignment is possible, so there is no attraction.

Use the simulation to apply an external magnetic field to different materials and watch what happens to their magnetic domains.

• In iron, domains align strongly when the field is turned on.
• In aluminum, domains don't exist — electrons are paired and no net alignment occurs.
• Copper is even less responsive: its electron configuration makes it diamagnetic, so it weakly repels a field.

If you heat a ferromagnetic material (like an iron nail) above its Curie temperature (about 770°C for iron), the thermal energy jumbles the domains so much that they can no longer align with an external field. The material becomes paramagnetic — still weakly magnetic, but no longer attracted strongly. This shows that ferromagnetism is a cooperative effect that depends on temperature.

• Above the Curie temperature, domain alignment is destroyed and ferromagnetism vanishes.
• Cooling the material below the Curie temperature restores its ferromagnetic properties.
• This boundary prevents the overgeneralization that 'ferromagnetic materials are always magnetic'.

A magnet attracts some materials because those materials are ferromagnetic: they contain magnetic domains that can rotate and align with the magnet's field. The alignment creates a net magnetic dipole, resulting in attraction. Materials without this property — copper, aluminum, plastic — are not attracted because their atomic structure prevents domain formation or alignment.

• Driving question: Why does a magnet attract some materials but not others?
• Answer: Only ferromagnetic materials (e.g., iron, nickel, cobalt, steel) have domains that can align with an external field, producing a strong attraction.
• All other common materials lack this alignment mechanism and are not attracted.
• The key insight: Magnetism is not a property of all metals, but a consequence of domain behavior inside certain elements.