Magnetism is a class of physical phenomena that are mediated by magnetic fields. Electric currents and the magnetic moments of elementary particles give rise to a magnetic field, which acts on other currents and magnetic moments. Magnetism is one aspect of the combined phenomenon of electromagnetism. The most familiar effects occur in ferromagnetic materials, which are strongly attracted by magnetic fields and can be magnetized to become permanent magnets, producing magnetic fields themselves. Demagnetizing a magnet is also possible. Only a few substances are ferromagnetic; the most common ones are iron, cobalt and nickel and their alloys. Because akmost all things in the universe have some magnetic field, all objects react on magnets, but only ferromagnetic materials are seen with strong force. For example if you move a magnet near a silver coin rapidly, the coin may move a little. Recent research show that if gold is heated, it becomes magnetic!
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