How Strong?

Magnets come in different strengths. Here's a quick way to compare them. Open a box of paper clips and dump them on a table. Hold a magnet close to the clips. How many paper clips cling to the magnet? What's your record? Part of this has to do with the actual size of the magnet - a magnet that is two inches in diameter will pick up more clips than a one-inch magnet. However, you may find that magnets of about the same size will grab very different numbers of paper clips!