Go through the following question and provide the answer:
An alkali metal A gives a compound B (molecular mass = 40) on reacting with water. The compound B gives a soluble compound C on treatment with aluminium oxide. Identify A, B and C and give the reaction involved.
i. A is
ii. When A reacts with water, it gives compound B. So, B is
iii. Compound C is
iv. The reaction involved is