When you are home, get (or borrow) a refrigerator magnet, and use it to pick up a single metal paper clip. Now bring the paper clip which is attached to the magnet close to a second paper clip. You will notice that you can pick up the second paper clip with the first one. The reason this happens is

• Paper clips are made of metal and all metals stick to magnets.
• The metal paper clip channels and concentrates the the magnetic force from the magnet so that a second paper clip can be picked up.
• The paper clip contains magnetic atoms which are aligned in the presence of the magnetic field produced by the magnet. The paper clip becomes magnetized (one end becomes a south pole and one a north pole) which then can attract a second paper clip.
• The paper clip is already magnetized and can pick up a second paper clip without the kitchen magnet's help.