1. Section 3

2. Quick Summary A magnet attracts other things made of iron, steel, and certain other materials. A magnet is surrounded by an invisible magnetic field. All magnets have two poles with opposite charges.

3. Vocabulary Magnetism Magnetic Field

4. What is the structure of a magnet? What are the similarities and differences between the north and south poles of a magnet? If you find a metal bar, how can you determine if it is a magnet?

5. If you break a magnet into two pieces, what happens to its magnetic poles? Use the Internet or other resources to locate places other than Magnesia where lodestone is found.

6. Quick Summary Earth is surrounded by a huge magnetic field. The needle of a compass aligns north-south so that one end points to Earth's magnetic north pole and the other end points to Earth's magnetic south pole. An aurora is caused by charged particles from the Sun being attracted to Earth's magnetic poles.

7. How does a compass work? Where are Earth's magnetic forces strongest? How does the existence of auroras on Jupiter provide evidence for Jupiter's magnetic field? Explain. What are some ways that Earth is like a magnet? Why does a compass needle point in a north-south direction? Expository Compasses can be used to create treasure hunts. Hide a small object. Then write clues on index cards. Hide all but the first clue, which tells how to use a compass to find the next clue, and so on. Challenge a friend to use your directions to find the hidden object.