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Co - Cobalt A transition metal, discovered by Brandt in 1735. We use cobalt chloride for its striking color change upon dehydration. Some of our students may observe the 423 nm emission line with an emission spectroscope.
Atomic number - 27 Density g/mL 8 .9
Atomic weight u 58 .9332 Melting point K 1768
Bonding radius A 1 .16 Boiling point K 3201
Atomic radius A 1 .67 Heat of vaporization kJ/mol 376 .5
Ionization Potential V 7 .86 Heat of fusion kJ/mol 16 .19
Electronegativity - 1 .88 Specific heat J/gK 0 .42
The oxide is amphoteric.
Crystal are hexagonal.
Electron config. : [Ar] 3d7 4s2
Definition: A definition can be applied that Cast Iron is an alloy of iron and carbon in which the carbon is in excess of the amount that can be retained in solid solution in austenite at the eutectic temperature. Carbon is usually present in the range of 1.8% to 4.5%, in addition, silicon, manganese, sulphur and phosphorus are contained in varying amounts. Various types of cast iron are covered by a British Standard classification and includes grey, malleable and white irons. Elements such as nickel, chromium, molybdenum, vanadium can be added to produce alloy cast irons.
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