Molybdenum Tech Report
Overview
Molybdenum was one of the first metals to be discovered by a modern chemist. It was found in 1781 by Swedish chemist Peter Jacob Hjelm (1746-1813). Hjelm's work on the element was not published, however, until more than a century later.
Molybdenum is a transition metal, placing it in the center of the periodic table. The periodic table is a chart that shows how chemical elements are related to one another.
Molybdenum is a hard, silvery metal with a very high melting point. It is used primarily to make alloys with other metals. An alloy is a mixture of two or more metals. The mixture has properties different from those of the individual metals. The most common alloys of molybdenum are those with steel. Molybdenum improves the strength, toughness, resistance to wear and corrosion, and ability to harden steel.
SYMBOL
Mo

ATOMIC NUMBER
42

ATOMIC MASS
95.94

FAMILY
Group 6 (VIB)
Transition metal

Physical properties
As a solid, molybdenum has a silvery-white metallic appearance. It more commonly occurs as a dark gray or black powder with a metallic luster. Its melting point is about 2,610°C (about 4,700°F) and the boiling point is 4,800 to 5,560°C (8,600 to 10,000°F). Its density is 10.28 grams per cubic centimeter.

Chemical properties
Molybdenum does not dissolve in most common chemical reagents. A chemical reagent is a substance used to study other substances, such as an acid or an alkali. For example, molybdenum does not dissolve in hydrochloric acid, hydrofluoric acid, ammonia, sodium hydroxide, or dilute sulfuric acid. These chemicals are reagents often used to test how reactive a substance is. Molybdenum does dissolve in hot strong sulfuric or nitric acids, however. The metal does not react with oxygen at room temperatures, but does react with oxygen at high temperatures.