Materials
 Bar Magnets 3
 Iron filings
 Sewing Needles ~10-20
 Cork Disks ~10-20
 Needle nose pliers ~3
 Bowls (or wide-mouthed cups) ~3
 Magnet disks ~10
 1 real compass
 Map of East Palo Alto
 Paper Clips
Warm-up activity (5-10 min): Show magnetic fields with iron files and a bar magnet.
Large Group Discussion (5 min):
What is magnetism?
Magnetism is an invisible force between certain types of materials.
What kinds of materials are magnetic?
Certain kinds of metals called “ferromagnetic” metals can interact with magnets.
A magnet (like the bar magnet) – creates a magnetic field that has two poles called North and
South. (Disk magnets, each face is a pole).
The Earth also has North and South poles (like bar magnet) and we can use a compass to detect
which way north is, and figure out other cardinal directions (East, West, South).
Homemade Compass (30 min):
 Magnetize the needle by rubbing the magnet against the sewing needle at least 12 times.
Always move it the same direction (ask students to keep track of whether they move the
magnets from the hole to the tip or the opposite way).
o This works because the needle is ferromagnetic and the magnet aligns all the
domains within the needle. We need the needle to be magnetized so it will
respond to the Earth’s magnetic field.
 Carefully push the needle through the cork disk (use the pliers if needed). Some students
might need help with this step. We want the same amount of needle showing on either
side of the disk.
 Fill a bowl with water, float the disk with needle so it can spin freely. Determine which
way the tip points after it has stopped moving.
 Does everyone’s compass point the same way?
 Use a map and a real compass to find north. Why is knowing the Cardinal directions
useful?
 How well did our homemade compass work?
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
Put a magnet next to your compass. What happens to the needle as the magnet is moved
close to it? How close does the magnet need to be to affect the compass?
o Why does the magnet alter the compass? Introduces another magnetic field.
The compass works because the magnetized needle interacts with the Earth’s magnetic
field. We can see how other magnetics interact (same poles repel; opposites attract)
Magnetized Paper Clip Chain (10 min):
A magnetized paper clip chain shows how magnetism can be created by induction. That means an
object can become magnetized itself if it is placed next to a magnetized object. Try this
science activity for kids to see how one paper clip in the chain magnetizes the next.
 Take a strong magnet, and hold a paper clip to it.
 Touch a second paper clip to the first one that is hanging from the magnet. The second
paper clip will be attracted to the first one because the first clip has become a magnet.
 Continue adding paper clips in this way to see how long of a chain you can create.
 Take the first paper clip off the magnet. Do the other paper clips stay joined together, or
do they immediately fall?
 The strong magnet aligns the magnetic domains in the paper clips, just like how we
magnetized the needles. Unlike the needle, the clips don’t stay magnetized very long after
the strong magnet is taken away.
Adapted From:
http://www.scientificamerican.com/article/steering-science-make-a-homemade-compass/
http://lifestyle.howstuffworks.com/crafts/other-arts-crafts/science-projects-for-kids-magnets-andmetal1.htm