Molybdenum is a transition metal, one of the elements that occur in Rows 4, 5, and 6 between Groups 2 and 13 in the periodic table. Its atomic number is 42, its atomic mass is 95.94, and its chemical symbol is Mo.

Properties

Molybdenum is a silvery white solid that usually occurs as a dark gray or black powder with a metallic luster. Its melting point is about 4,730°F (2,610°C), its boiling point is between 8,670 and 10,040°F (between 4,800 and 5,560°C), and its density is 10.28 grams per cubic centimeter.

Molybdenum is not very active. It does not react with cold acids or with oxygen at room temperature, although it does become more active at higher temperatures. For example, it does react with hot, strong sulfuric or nitric acids. It also reacts with oxygen at high temperatures to produce molybdenum trioxide (MoO₃).

Occurrence and Extraction

Molybdenum never occurs as the free element in...