Hobbies And Interests
Metal in Your Cereal
Crush cereal flakes onto a large dinner plate, using enough flakes to form a layer of crumbs on the plate. Move your magnet across the crumbs without touching them. Any flakes that move as the magnet passes over them contain iron particles. An alternative to this is to float a few whole flakes in a bowl containing water. Pass the magnet slowly across the plate until one or more flakes moves toward it. These flakes contain particles of iron. Pull the flakes across the surface of the water, or spin them around. You can link a number of flakes together, if more than one contains iron.
Metal Paper Clips
Sixth-grade students can prove a magnet̵7;s lines of force are transmitted through metal paper clips. The best magnet to buy is a neodymium magnet, which is at least 10 times more powerful than ceramic magnets. You can find these magnets in computer disk drives and in some speakers. Use your magnet to pick up the first paperclip and then pick up more paperclips with the one hanging from the magnet. The magnet has passed its lines of force to the first paperclip through induction; because of this principle you can gather a number of paperclips, each one attaching to the previous one.
Metal as a Conductor
With two nails, a short piece of insulated wire and a lemon, you can show how metals serve as conductors. Remove about 1-inch of the plastic coating from the ends of two, 6-inch pieces of insulated wire. Wrap one end of each wire around a metal nail. Use one copper and one zinc nail and push these into the lemon. Students will feel a tingling when they touch the two free ends of wire to their tongue.
Copper Nails
Add a strong solution of copper sulphate to a glass container of tap water. Place one or two iron nails into this solution and leave it in the copper sulphate mixture for a few seconds. These nails will be coated by copper, once you remove them from the glass container. The copper from your solution has attached to the nails, through the transfer of electrons.