Question

carbon cannot reduce the oxide of magnesium or calcium why

Answer 1

as they occupy top levels in reactivity series so they are highly reactive. therefore , they also react with carbon . so, reducing agents like carbon are not used

Answer 2

This is because sodium and magnesium are more reactive than carbon. This means that carbon cannot reduce the oxides of these metals. The two metals are above carbon in the reactivity series and thus have a high affinity to oxygen than carbon does and thus cannot be reduced by it.