A 99.9% electrolytically refined cobalt has a lustrous grey metallic colour. But it forms different colours when reacts with other elements like oxygen etc forming the different oxide. Cobalt (II) aluminate is called cobalt blue which is a blue pigment. Another is Cobalt (II) chloride hexahydrate which is a halide and has a pink colour. Cobalt (II) bromide has a green colour, solid and soluble in water.
How many valence electrons does cobalt have?
The electronic configuration of Cobalt is 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d7. Cobalt has nine valence electrons.
When was cobalt discovered?
Cobalt was discovered and isolated by a Swedish chemist by the name Georg Brandt in 1735.
Where is cobalt found?
Free cobalt is not found on Earth because of its reactivity. It reacts quickly with oxygen when exposing to air and in water with chlorine. The Earth's crust is comprised about 0.0029% of cobalt in a combined form with other impurities. It could be extracted from different minerals like cobaltite, glaucodot, skutterudite and cattierite. About 60 % of the World supplies are coming from the Democratic Republic of the Congo's Katanga Province.