Activity 6: Magnet Uses
MOTHER NATURE'S MAGNET
Everyone has seen a magnet, but aside from decorating a refrigerator, what are its uses? Students will investigate the history of magnets and explore some of the ways that we use magnets.
To understand the uses of magnets in our everyday lives.
Students will be able to:
Activity: 30 min.
Over twenty-five hundred years ago, the Greeks discovered the first magnet. It was a naturally occurring rock with magnetic properties called lodestone, also known as magnetite. Magnetite is an iron ore whose molecules are aligned to give it magnetic properties. A thousand years later, the Chinese invented the first crude compass, composed of magnetic rock suspended on a string. When knowledge of this rock was brought to Europe in the fourteenth century, improvements were made and explorers like Magellan and Columbus were able to use it to navigate around the world.
When an object is magnetized and suspended from a string it becomes free to align itself with larger magnetic fields. Early compasses were constructed in this manner. The suspended object aligns itself with Earth's magnetic field and points north, helping navigators keep oriented.
Magnet molecules are all aligned in the same direction. The cooperative pull of each molecule causes a huge pull in that direction. When a magnet is exposed to metallic objects, it pulls on the metallic molecules and causes it to be attracted. This is why magnets will 'stick' to metals. Some metals will not be attracted by magnets. Their molecular properties do not facilitate the magnetic or molecular pull.
Besides refrigerator and compass magnets, magnets have an extraordinarily large number of uses including: holding objects, moving objects, suspending objects, making electricity, jewelry, medicinal purposes, navigation equipment, inspiration for bad poetry, and maintaining the digestive health of a cow, just to name a few. (Cow magnets are sold in ranch stores and fed to cows. The magnet sits in the stomach of the cow and attaches itself to any bits of metal the cow might ingest, holding it there so it doesn't injure the cow further).
How could we use this stone? What are other historic uses of magnets? Who invented the compass? What is a compass? How do we use a compass? What could we do to turn this stone into a compass? Why do big pieces of this stone and other compasses point north?
Challenge students to a magnetic scavenger hunt. Now that they have the skills to test if an object is a magnet, have them spend a day of homework listing as many uses of magnets as they can find. Create a class list and post it.
Included National Parks and other sites:
Utah Science Core:
Kindergarten Standard 4 Objective 1,2,3