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Concepts: Magnetization of ferromagnetic materials can be accomplished by exposure to an external magnetic field. Magnetism is caused by the alignment of magnetic domains, regions in which electron spins are aligned.
Summary: Students magnetize straight pins and build tadpole compasses. They magnetize an iron rod by stroking it with a permanent magnet and learn how striking (or heating) the rod destroys its magnetism. They examine lodestone and use a model to develop magnetic domain concepts. Optional activity includes heating nails and then cooling them in the field of a bar magnet and the planet.
Objectives Links:
III. D. Magnetostatics
Process Skills Checklist
Equipment:
- compass
- straight pin
- large nails or iron rods
- size 00 cork
- permanent bar and stirring magnets
- lodestone
- glass tube with iron fillings
- paperclips
- petri dish
- (Optional: hammer, Bunsen burner, tongs)
Safety Concerns:
Caution with flame and hot nails if heating option is used.
Revision Date: December 2003
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