1) Although all atoms have moving electric charges, not all materials are magnetic (for example, copper or wood are not magnetic). Why, then, aren't all materials magnetic?
2) A magnet is used to pick-up three paper clips as shown on the right. Explain how the magnet is able to do this?
3) The ability of the magnet to pick-up these paper clipsimplies that the earth's gravitational field is very weak compared to the magnetic force ofthe magnet. Why is this so?