Lithium nitrate on heating gives

Which of the following statement(s) are correct, when alkali metals burn in the presence of oxygen?

I. Lithium forms monoxide

II. Sodium forms peroxide

III. Potassium, rubidium and cesium forms superoxide

Which alkali metal emits blue colour light in flame test?

The carbonates of alkaline earth metals decompose on heating to give

I. $\mathrm{CO}_2$

II. Metal oxide

III. $\mathrm{H}_2 \mathrm{O}$

IV. CO