What is Magnetism?
Magnetism is an invisible force or field caused by the unique properties of certain materials. In most objects, electrons rotate in different random directions. This causes them to cancel each other out over time. However, magnets are different. In magnets, the molecules are arranged nicely so that their electrons rotate in the same direction. This arrangement of atoms creates two poles in a magnet, a north pole and a south pole.
Magnets Have Magnetic Fields
The magnetic force in a magnet runs from the North Pole to the South Pole. This creates a magnetic field around a magnet.
Have you ever held two magnets together? They don’t act like most subjects. If you try to bring the South Poles together, they will repel each other. The two north poles also repel each other.
Spin a magnet and the North (N) and South (S) poles are attracted to each other. Like protons and electrons, opposites attract.
Where do we get Magnets?
Only a few materials have the right kind of structure to allow electrons to line up just to make a magnet. The main material we use in magnets today is iron. Steel contains a lot of iron, so steel can also be used.
The Earth is a Giant Magnet
At the center of the Earth, the Earth’s core rotates. The core is composed mainly of iron. The outer part of the core is liquid iron that rotates and turns the earth into a giant magnet. This is where we get the names of the north and south poles. These poles are actually the anode and cathode of the Earth’s giant magnet.
This is very useful to us here on Earth because it allows us to use the magnets in the compass to find our way and make sure we are on the right track. It is also useful for animals like birds and whales to use the earth’s magnetic field to find the right direction when migrating. Perhaps the most important feature of the Earth’s magnetic field is that it protects us from wind and solar radiation from the Sun.
The Electric Magnet and Motor
Magnets can also be generated electrically. By wrapping a wire around an iron rod and passing an electric current through the wire, it is possible to create powerful magnets. This is called electromagnetism. The magnetic field generated by an electromagnet can be used in a variety of applications. One of the most important is the electric motor.