Cobalt Tech Report
Overview
Humans have been using compounds of cobalt since at least 1400 B.C. The compounds were used to color glass and glazes blue. In 1735, Swedish chemist Georg Brandt (1694-1768) analyzed a dark blue pigment found in copper ore. Brandt demonstrated that the pigment contained a new element, later named cobalt.
Cobalt is a transition metal, one of several elements found in Rows 4 through 7 between Groups 2 and 13 in the periodic table. The periodic table is a chart that shows how chemical elements are related to each other. Cobalt is located between iron and nickel and shares many chemical and physical properties with these two elements.

SYMBOL
Co

ATOMIC NUMBER
27

ATOMIC MASS
58.9332

FAMILY
Group 9 (VIIIB)
Transition metal

Physical properties
Cobalt is a hard, gray metal that looks much like iron and nickel. It is ductile, but only moderately malleable. Ductile means capable of being drawn into thin wires. Malleable means capable of being hammered into thin sheets.
Cobalt is one of only three naturally occurring magnetic metals. The other two are iron and nickel. The magnetic properties of cobalt are even more obvious in alloys. An alloy is made by melting and mixing two or more metals. The mixture has properties different from those of the individual metals.
The melting point of cobalt metal is 1,493°C (2,719°F), and the boiling point is about 3,100°C (5,600°F). The density is 8.9 grams per cubic centimeter.

Chemical properties
Cobalt is a moderately reactive element. It combines slowly with oxygen in the air, but does not catch fire and burn unless it is in a powder form. It reacts with most acids to produce hydrogen gas. It does not react with water at room temperatures.