Atomic Number: 27 Period Number: 4 Group Number: 9
Cobalt is a hard, silver-gray metal. It exists in nature in two primary ores--cobaltite(CoAsS) and erythrite [Co3( AsO4)2]. 59Co is the only stable cobalt isotope exist in nature.
Cobalt alloy is an important material in industry. Alnico, an alloy consisting of aluminum, nickel and cobalt is used to make powerful permanent magnets. Stellite alloys, which contain cobalt, chromium and tungsten, are used to make high-speed and high temperature cutting tools and dyes. Cobalt is also used to make alloys for jet engines and gas turbines, magnetic steels and some types of stainless steels.
Lithium cobalt oxide( LiCoO2) is widely used in lithium ion battery and Cobalt is also an essential element in making blue pigments.
Physical and Chemical properties:
Atomic Weight: 58.933195
Melting Point: 1768 K
Boiling Point: 3200 K
Density: 8.86 g/cm3
Phase at Room Temperature: Solid
Element Classification: Metal
Ionization Energy: 7.881 eV
Oxidation States: +3, +2
Wikipedia - Basics on Cobalt
WebElements - The basic elements of Cobalt
Jefferson Lab - Learning about Cobalt