Walk as fast as you can in a circle around a section of the pool that's about 3 feet deep (the more people, the better the effect). Do about 20 laps, then change direction for 10 laps. The resulting rush of water against your body will feel much like the jets in a whirlpool.
Elements and Compounds. All matter in the natural world is composed of one or more of the 92 fundamental substances called elements. An element is a pure substance that is distinguished from all other matter by the fact that it cannot be created or broken down by ordinary chemical means.
Rocks are mixtures formed of minerals. Just as elements are the building blocks of minerals, so minerals form the building blocks of rocks. Table 1 gives some information about the most common elements in the Earths crust in order of abundance. The other elements include copper, uranium, gold and silver. Although they are comparatively rare, these are very important to mankind.