Magnets
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. But a positively charged thing will pull toward a negatively charged thing. We call this pulling and pushing "magnetism."
Many objects in space are magnetic. The Sun, for instance, is very magnetic, because there are places on the Sun where there are a lot of extra electrons or protons. The whole Earth is also highly magnetic, although Mars and Venus are much less so. The Earth's magnetism pulls negatively charged things like electrons toward the North Pole and positively charged things like protons toward the South Pole. Liquid iron inside the Earth creates (and sometimes changes) the Earth's magnetism.
A lodestone
Small iron rocks on the surface of the Earth are also sometimes naturally magnetic. Inside these iron oxide rocks, which we call lodestones, each iron atom is a tiny magnet, with the 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, but 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.
Until about two hundred years ago, people made magnets by rubbing iron on lodestones. The rubbing lined up the atoms of the iron so that all the atoms would pull in the same direction. But today we can use electricity to make magnets.
Find out about Electromagnets
Learn by Doing - Magnets
The invention of the compass
Main Electricity page
To find out more about magnets and electricity, check out these books from Amazon.com or from your library:
