Group 12 element is a common reducing agent in organic synthesis, and is also used in high-pressure sodium lamps. Mercury readily combines with aluminium to form a mercury-aluminium amalgam when the two pure metals come into contact. Since the amalgam reacts with air to give aluminium oxide, small amounts of mercury corrode aluminium. For this reason, mercury is not allowed aboard an aircraft under most circumstances because of the risk of it forming an amalgam with exposed aluminium parts in the aircraft. Most of the chemistry has been observed only for the first three members of the group 12. The chemistry of copernicium
Dental amalgam controversy expansion and contraction of the various amalgam products. During the American Civil War, the debate on the merits of amalgam continued. In dental meetings, with now decades of use and dental research came the recognition of the importance of good technique and proper mixture on long-term success. It was argued that, "the fault was not in the material but in the manipulation...Some men's amalgam is good universally, and some men's gold is bad universally; the difference lies in the preparation of the tooth and in the plug (filling)." More controversy came in 1872, when an amalgam filling was reported as