Stickers: What Materials are Attracted to a Magnet?
What materials are attracted to a magnet?
- testing materials: aluminum foil, copper wire, glass marble, iron nail, paper, steel BBs, wooden match
- bar magnet
- Lay the testing materials on a wooden table.
- Touch the magnet to, and slowly move the magnet away from, each material.
- Observe and record which materials cling to the magnet.
The iron nail and the BBs are the only materials that cling to the magnet.
All materials, including the testing materials, are made up of tiny bits of matter called atoms. For example, the smallest part of an iron nail is an atom of iron, and the smallest part of a glass marble is an atom of glass. Materials are magnetic because of the way their atoms group together.
When clusters of atoms organize themselves, the atoms are attracted to different areas of the earth's magnetic field. One side of the cluster is attracted to the earth's magnetic north pole and the other side is attracted to the earth's magnetic south pole. These clusters of atoms are called domains. In magnetic materials, many of the domains line up with their north poles pointing in the same direction. This makes the material magnetically dipolar (having both a north and a south pole). The more uniform the arrangement of domains, the stronger the magnetic property of the material. Nonmagnetic materials do not have domains.
Magnets, like the one you used in the experiment, are made from iron, cobalt, and nickel (or alloys of these metals). The arrangement of the metal atom domains that make up the magnet creates a very strong magnetic property. The only two testing materials with magnetic properties were the iron nail and the BBs (made from steel, which contains iron), so they were the only materials to cling to the magnet
- Are BBs and iron nails the only magnetic materials? Repeat the experiment using testing materials that are not on the materials list Keep a record of the materials that are found to be magnetic. Science Fair Hint: This record can be used as part of a written report to be displayed with your project
- Does the magnet have to touch the testing material to attract it? Repeat the original experiment, holding the magnet very near, but not touching, the materials. Science Fair Hint: Display photographs taken during the experiment that show magnets held at different distances from each testing material. Include photos of magnetic materials clinging to a magnet and record a measurement of the height the material moved to reach the magnet. Try to determine which materials have the strongest magnetic properties.
- Magnetic screwdrivers are useful when working with very small screws. The screw attaches itself to the magnetized tool and is prevented from being dropped. Find out more about the uses of magnets. You can display a poster with pictures representing these uses.
- As part of an oral presentation, demonstrate how a magnet can be used to separate magnetic and nonmagnetic materials. Combine 1 teaspoon (5 ml) of salt and 1 teaspoon (5 ml) of iron filings. You can find iron filings inside some magnetic drawing toys sold at toy stores.) Pour the mixture onto a sheet of paper. Pass a bar magnet near, but not touching, the surface of the mixture. The iron filings will cling to the magnet and the salt will stay on the paper.
Check It Out!
The ability of magnets to separate magnetic materials from nonmagnetic materials is important in many industries. Read about magnets and prepare a chart showing what you have learned. Some examples of magnets being used as separators are:
- metals separated from ore.
- archaeologists recovering sunken treasure from the ocean floor with a magnetic sweeper.
- food manufacturers preventing small iron particles that rub off of machinery from mixing with food.
- vendors sorting nonmagnetic coins from magnetic slugs and washers that are dropped into vending machines.
Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state’s handbook of Science Safety.