What is Ellingham diagram? $(3\%)$ Explain why oxidation reactions involving solid phases $($ex$.A_{(s)}+O_{2(g)}A{O}_{2(s)}$ and $($:$B_{(s)}+O_{2(g)}B{O}_{2(s)}\}$ have similar line slope in an Ellingham diagram. $(3\%)$ Discuss the effect of phase transformations $($phase change in a reactant or product of the reaction$)$ on the Ellingham diagram. $(3\%)$ What is the application of the Ellingham diagram? $(3\%)$