Suggest one physical property of molybdenum that is characteristic of a transition element.
Suggest one chemical property of molybdenum compounds that is characteristic of compounds of transition elements.
Molybdenum steel is an extremely hard alloy. Using ideas about metallic structure, suggest why molybdenum steel is much harder than pure iron. A labelled diagram may help you answer this question.
Molybdenum steel is prepared by reducing a mixture of $\text{MoO}_3$ and $\text{Fe}_2\text{O}_3$ with aluminium. $\text{MoO}_3+2\text{Al}\rightarrow\text{Mo}+\text{Al}_2\text{O}_3$ $\text{Fe}_2\text{O}_3+2\text{Al}\rightarrow2\text{Fe}+\text{Al}_2\text{O}_3$ Molybdenum steel contains 20.0% by mass of molybdenum. Calculate the mass of $\text{MoO}_3$ needed to make 1000 g of molybdenum steel. Give the answer to three significant figures. [The relative atomic mass for molybdenum, Mo, is 96.]