Which of the following compounds is consumed during the preparation of $Na_2CO_3$ by Solvay's process?

The characteristic not related to alkali metal is

Which of the following statements is false for alkali metals?

The $s$-block elements are characterised by their larger atomic sizes,lower ionisation enthalpies,invariable $+1$ oxidation state and solubilities of their oxosalts. In the light of these features,describe the nature of their oxides,halides and oxosalts.

Which of the following is the most important factor in making lithium metal the strongest reducing agent?

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 form superoxide