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.

(A) The atoms of alkali metals have a large size,and due to this,they readily form cations,making their compounds ionic in nature. Alkali metals exhibit a $+1$ oxidation state and form ionic compounds.
Alkali metals form three types of oxides: Normal oxides $(M_{2}O)$,Peroxides $(M_{2}O_{2})$,and Superoxides $(MO_{2})$.
The basic character of normal oxides increases from $Li_{2}O$ to $Cs_{2}O$ due to an increase in their ionic character.
Halides of alkali metals $(MX)$ are generally ionic,except for $LiX$,which is covalent due to the small size and high polarizing power of the $Li^{+}$ ion.
Oxosalts: All alkali metals form solid carbonates with the general formula $M_{2}CO_{3}$. These carbonates are stable,except for $Li_{2}CO_{3}$,which is unstable and decomposes due to the high polarizing capacity of $Li^{+}$. All alkali metals (except $Li$) form solid bicarbonates $(MHCO_{3})$. All alkali metals form nitrates with the formula $MNO_{3}$,which are colourless,water-soluble,electrovalent compounds.