SCIENCE FOR YEAR 3: November 2011

Magnets Attract Some Materials.

A. MAGNETIC OBJECTS.

Thumbtacks

Steel Spoon

Iron nail

Objects that are made of iron, steel or nickel can be attracted by magnets. They are called magnetic objects.

B. NON-MAGNETIC OBJECTS.

Objects that are made of wood, plastic, glass or gold cannot be attracted by magnets. They are called non-magnetic objects.

Which Magnet Is The Strongest?

Which Magnet Is the Strongest?
A good way to test how strong different magnets are is to see how many magnetic objects it can attract. Try this experiment with your magnets!
What You Will Need:

Several magnets
Box of paperclips
Notebook
Pencil
Someone to help you

What To Do:

Have your helper hold on to one end of one of the magnets. Stick one paperclip to the other end of the magnet. One end of the paperclip should dangle off the magnet. (Your magnet may be really strong, so you may need your helper to hold the paperclip so just an end is touching the magnet rather than the side of the paperclip, like in the picture.)
Now touch another paperclip to the end of the first paperclip to start a paperclip chain. Keep adding paperclips until no more stick to the chain. In your notebook, write down how many paperclips the magnet was able to hold together in a chain before paperclips started to fall off.
Do steps 1 & 2 with the other magnets, recording in your notebook how many paperclips would stick in a chain to each magnet.

What's Happening?
When a magnet touches another magnetic object (such as a paperclip), the object becomes a temporary magnet for as long as it is touching the real magnet! It can now be used to pick up more paperclips. Each additional paperclip also becomes a temporary magnet with a weaker magnetic force than the one before it. Some magnets may be able to hold a chain of five paperclips while another magnet may only be able to hold one or two paperclips. How many paperclips a magnet can hold is a good indication of its strength. If you have a strong enough magnet and lift up the paperclips long enough, you may find that some of the paperclips will keep the ability to act like magnets for a little while even when they are not touching the magnet. If this happens, you have just made a very strong temporary magnet.

All About Magnets

What is a Magnet?
That's a great question and one that you just might have to see for you to really understand. Be sure to do the science projects in this issue to learn how and why magnets work!
Project 1: What's the Attraction?
All magnets have the ability to attract other magnets or magnetic objects (such as iron and some other metal objects). But a magnet doesn't necessarily have to touch a magnetic object for the object to be attracted to it.
What Is a Magnet?
A magnet is a solid object, usually a rock or piece of metal, that has the ability to attract certain materials. To help discover what is and what is not attracted to magnets, go on a magnet hunt. Look around the room and help your child make a list of objects he or she thinks will be attracted to the magnet as well as a list of objects that will not be attracted. After making your lists, test each of the objects. (Don't use magnets on computers, cassette tapes, discs, and other electronic devices - it could damage the magnets inside of them!) Compare your results with what you predicted would be attracted. Were you correct on all your predictions? Were you wrong on any? Discuss why items did or did not stick when you originally thought the opposite would be true. For instance, the object is made out of plastic but coated with shiny paint to make it look metallic; not all metals are attracted to magnets; or maybe just parts of an object were attracted to the magnet. What does this tell us about magnetic attraction? (That an object must be made out of metal to be attracted, but not all metals are attracted.) Metals such as iron, nickel, and cobalt are attracted to magnets. Steel has iron in it, so it is also attracted to magnets.
Alternatively, you can use this coloring page as part of a magnet hunt. Go around the house and find things that are magnetic. Circle the items on the coloring sheet that are attracted to the magnet and draw in any other items you found that are also magnetic.
As mentioned before, many common household items have magnets in them and are part of what makes these items work. Electronic devices such as refrigerators, washing machines, lamps, telephones, TVs, and stereos all have magnets in them.