Some Physical Properties of Molybdenum

There are five principal reasons for the use of molybdenum as an alloying element in steels and cast irons. 

At least nine oxides of molybdenum have been reported , but of these the monoclinic dioxide MoOj and the orthorhombic trioxide are the most common and most stable. The others, with formulae lying between M0O2 and M0O3 are metastable mixed valency oxides with intense colour and metallic lustre, formed from one or both 

---