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.
1 Gemstones, like rubies, emeralds and sapphires, are crystals. The elements they are made up of determine their color.  A unit cell is what they call the basic building block of a crystal. It is the smallest arrangement of atoms that shows the crystal structure.