Metal leaf metal leaves, has been known for more than 5,000 years. Metal leaf A metal leaf, also called composition leaf or schlagmetal, is a thin foil used for decoration. Metal leaves can come in many different shades. Some metal leaves may look like gold leaf but does not contain any real gold. This type of metal leaf is often referred to as imitation leaf. Metal leaves are usually made of gold (including many alloys), silver, copper, aluminium, brass (sometimes called "Dutch metal" typically 85% Copper and 15% zinc) or palladium, sometimes also platinum. Vark is a type of silver leaf used
Alkali metal is very useful as a heat-exchange liquid in fast breeder nuclear reactors due to its low melting point, viscosity, and cross-section towards neutron absorption. Potassium compounds are often used as fertilisers as potassium is an important element for plant nutrition. Potassium hydroxide is a very strong base, and is used to control the pH of various substances. Potassium nitrate and potassium permanganate are often used as powerful oxidising agents. Potassium superoxide is used in breathing masks, as it reacts with carbon dioxide to give potassium carbonate and oxygen gas. Pure potassium metal is not often used, but its alloys with