The least stable oxide at room temperature is

In the metallurgy of aluminium,cryolite is mixed in the molten state because it

Which of the following is electrolyzed for the extraction of aluminum?

Which of the following processes involves smelting?

Explain the extraction of elements by oxidation.

Given below are two statements.
Statement $I$: According to the Ellingham diagram,any metal oxide with higher $\Delta G^{\circ}$ is more stable than the one with lower $\Delta G^{\circ}$.
Statement $II$: The metal involved in the formation of oxide placed lower in the Ellingham diagram can reduce the oxide of a metal placed higher in the diagram.
In the light of the above statements,choose the correct answer from the options given below.