On combustion of $Li$,$Na$,and $K$ in excess of air,the major oxides formed,respectively,are:

The correct statements are:
$I$. The low solubility of $LiF$ is due to its high lattice enthalpy.
$II$. $LiBr$ is soluble in acetone.
$III$. $LiCl$ is soluble in pyridine.
$IV$. The order of melting points of alkali metal halides is $MF > MCl > MBr > MI$.

$KO_2$ finds use in oxygen cylinders used for space and submarines. The fact$(s)$ related to such use of $KO_2$ is/are:

Among $KO_2$,$AlO_2^-$,$BaO_2$,and $NO_2^+$,in which species is an unpaired electron present?

Which one of the following nitrates will leave behind a metal on strong heating?

Identify the correct statements about alkali metals.
$A$. The order of standard reduction potential $(M^{+} \mid M)$ for alkali metal ions is $Na > Rb > Li$.
$B$. $CsI$ is highly soluble in water.
$C$. Lithium carbonate is highly stable to heat.
$D$. Potassium dissolved in concentrated liquid ammonia is blue in colour and paramagnetic.
$E$. All the alkali metal hydrides are ionic solids.
Choose the correct answer from the options given below.