Thermite is a mixture of iron oxide and which of the following?

The metal extracted by the electrolysis of its fused salt is

In the manufacture of iron from haematite,the function of limestone is as

In the equation,$4M + 8CN^{-} + 2H_2O + O_2 \to 4[M(CN)_2]^- + 4OH^{-}$,the metal $M$ is

At a site,low grade copper ores are available and zinc and iron scraps are also available. Which of the two scraps would be more suitable for reducing the leached copper ore and why?

Is it true that under certain conditions,$Mg$ can reduce $Al_2O_3$ and $Al$ can reduce $MgO$? What are those conditions?