When alkali metals are heated in excess of air. What is the nature of oxides formed?

(a) When alkali metals are heated in excess of air. What is the nature of oxides formed ?
(b) How can you prepare baking soda?
© Which is more reducing, alkali metals or ; alkaline earth metals ?
(d) Alkaline earth metals impart a characteristic colour to the flame but Be and Mg do not ; why ?
(e) Write general configuration of alkali and alkaline earth metals.