aluminum (Al) /əlo̅o̅″minəm/ [L, alumen, alum] , a widely used metallic element and the third most abundant of all the elements. Its atomic number is 13; its atomic mass is 26.97. Aluminum is commonly obtained by purifying bauxite to produce alumina, which is reduced to aluminum. It is light and durable and used extensively in the manufacture of aircraft components, prostheses, and dental appliances. Its compounds are components of many antacids, antiseptics, and astringents. Aluminum salts, such as aluminum hydroxychloride, can cause allergic reactions in susceptible individuals. Aluminum hydroxychloride is the most commonly used agent in antiperspirants and is also effective as a deodorant.
