Classification of microbes based on specific nutritional requirements. Heterotroph = use carbon sources (sugars, alcohols, carbs, fats, proteins) Autotroph = use inorganic carbon source (CO2) Chemotroph = use organic (glucose)/inorganic (reduced Fe2+) chemicals for energy.
You can color any metal containing iron, such as steel, with the oven heat of an ordinary kitchen range. Depending on the temperature setting, the steel changes color across a spectrum of shades ranging from pale yellow to dark blue. In addition, literally hundreds of chemicals will change the color of metal surfaces. Some of them are too toxic for amateurs to use. For example, cyanides, nitric acid, chromic acid, mercuric chloride, and lead acetate are hazardous chemicals only professionals should attempt to use.
Additive color is light created by mixing together light of two or more different colors. Red, green, and blue are the additive primary colors normally used in additive color systems such as projectors and computer terminals.