Plastics
. Plastics, materials made up of large, organic (carbon-containing) molecules that can be formed into a variety of products. The molecules that compose plastics are long carbon chains that give plastics many of their useful properties. In general, materials that are made up of long, chainlike molecules are called polymers . The word plastic is derived from the words plasticus (Latin for “capable of molding”) and plastikos (Greek “to mold,” or “fit for molding”). Plastics can be made hard as stone, strong as steel, transparent as glass, light as wood, and elastic as rubber. Plastics are also lightweight, waterproof, chemical resistant, and produced in almost any color. More than 50 families of plastics have been produced, and new types are currently under development. Like metals, plastics come in a variety of grades. For instance, nylons are plastics that are separated by different properties, costs, and the manufacturing processes used to produce them. Also like metals, some plastics...