Atomic number 42
Valencia 2,3,4,5,6
Oxidation state +6
Electronegativity 1.8
Covalent Radius (Å) 1.45
Ionic Radius (Å) 0.62
Atomic radius (Å) 1.39
Electronic configuration [Kr] 4d55s1
First ionization potential (eV) 7.24
Atomic mass (g / mol) 95.94
Density (g / ml) 10.2
Boiling point (ºC) 5560
Melting point (ºC) 2610
Molybdic acid, H2MoO4 (or MoO3.H2O), forms a stable series of normal salts, of the type M22 + MoO4, M2 + MoO4 and M23 + (MoO4) 3. Polymeric molybdates or isopolymolybdates can be formed by acidification of a molybdate solution or, in some cases, by heating normal molybdates. Hydrogen peroxide reacts with various molybdates to form a series of peroxyanionic compounds.
Another group of molybdenum compounds are the heteropolyelectrolytes, by far a fundamental family of salts and free acids: each member contains a complex and high molecular weight anion.
Molybdenum forms compounds in which it has oxidation states, 0, 2+, 3+, 4+, 5+, 6+. It has not been observed as an ionizable cation, but cationic species such as molybdenyl are known. Molybdenum chemistry is extremely complex and, with the exception of halides and chalcogenides, very few simple compounds are known.
Molybdenum dioxide and trioxide are the most common and stable oxides; other oxides described are metastable and are essentially laboratory species.
It is broad in stability and a series of compounds homologous with S, Se and Te, similar to oxides.