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1 Chemistry Option A Magnets 11 - If you break a magnet
Have you talked about your ideas? Do you agree with any of the characters or do you think something different? Do you all have the same ideas? Here are some ways of finding out more. Get an iron nail and use a saw to cut partway through it. Make it into a magnet by stroking it in one direction with a permanent magnet. See how many paper clips it picks up. Now break it in half and investigate the two separate pieces. What do you find? Put two bar magnets together so that the ends attract each other. What are the properties of this double-size magnet?
Here’s what a scientist might say. Did you find any evidence to support or justify these ideas? Are there any questions that you still need to answer? Magnetic materials, like iron, have groups of atoms in them that have magnetic properties. These regions are called domains. The motion of the electrons in these domains creates a magnetic field and the domains are like little magnets. If all the domains line up in the same direction the whole material becomes a magnet. Magnets can be made by stroking a piece of iron with a strong magnet, so all the domains in the iron line up in the same direction. If the domains are not lined up the magnetism is weak or non-existent. The magnetism only changes if the atoms in the domains are rearranged. Cutting a magnet in half does not change the way the domains are lined up, so each half acts like a magnet. However there are fewer domains in each half, so each half is weaker than the whole magnet. The magnetic domains each have a north and south pole so it isn't possible to get one pole on its own. Scientists are investigating making tiny magnets out of single atoms. What can you find out about this? Share your ideas for creative uses for nanomagnets.