Iron Picture
Iron (symbol: Fe atomic number: 26) was used prehistorically: An iron pillar, dating to about A.D. 400, remains standing today in Delhi, India. This solid shaft of wrought iron is about 7 1/4 m high by 40 cm in diameter. Corrosion to the pillar has been minimal although it has been exposed to the weather since its erection. Iron is a relatively abundant element in the universe. It is found in the sun and many types of stars in considerable quantity. Its nuclei are very stable. The metal is the fourth most abundant element, by weight that makes up the crust of the earth. The most common ore is hematite, which is frequently seen as black sands along beaches and banks of streams. Common irons is a mixture of four isotopes. The pure metal is not often encountered in commerce, but is usually alloyed with carbon or other metals. The pure metal is very reactive chemically and rapidly corrodes, especially in moist air or at elevated temperatures. Carbon steel is an alloy of iron with small amounts of Mn, S, P, and Si. Alloy steels are carbon steels with other additives such as nickel, chromium, vanadium, etc.