How do magnets work?

Magnetism is a force created by electricity. When a thing has more electrons than it has protons, it has a negative charge. If it has more protons than electrons, it has a positive charge. If you put two things with negative charges near each other, they push apart from each other, and so do two things with positive charges. A positively charged thing will pull toward a negatively charged thing. We call this pulling and pushing, “magnetism.”

Small iron rocks on the surface of the Earth are also sometimes naturally magnetic. Inside these iron oxide rocks, called lodestones, are iron atoms that are tiny magnets that have electrons moving around and around in a circle that sets up a magnetic field. In ordinary iron, the atoms are jumbled up so that they all pull in different directions. In a lodestone the iron atoms have gotten lined up so that most of them pull in the same direction, making the lodestone into a big magnet.

Magnets are usually made of metal iron or another material that has a lot of iron in it. Magnets cans be in many shapes and sizes, but all of them have the ability to pull things toward themselves. Magnets only attract or pull metals that are made of iron or contain iron.

Magnetism is concentrated around the poles, or ends, of a magnet. A magnet has a north pole and a south pole. The two poles may look the same, but they behave differently from each other. If you put one pole of a magnet near the pole of another magnet, you may feel an attraction (pulling) force as the two poles stick together, or you may feel a repulsion (pushing) force, as the two poles push away from each other. It has been shown by experiments that like poles repel each other, and unlike poles attract each other.

The space surrounding a magnet where the magnetic force is exerted is called a magnetic field. If a magnet is placed in such a field, it will experience magnetic forces. The field will continue to exist even if the magnet is removed. In many ways, our Earth is like a big magnet. Lines of magnetic force run through the planet. And, just like a magnet, Earth has a north pole and a south pole.

When current flows in a wire, a magnetic field is created around the wire. From this it has been shown that magnetic fields are produced by the motion of electrical charges. A magnetic field of a magnet results from the motion of negatively charged electrons in the magnet.

You cannot see the magnetic force around a magnet, but you can see the effects of its presence when an iron nail sticks to a magnet. You can see the shape of a magnetic field by using tiny, powder-like pieces of iron, called iron filings, which reveal that the lines and strength of the magnetic force are concentrated around and between the poles at the end of the horseshoe magnet. On a bar magnet, they line up to show how the magnetic force spreads out from the poles.