Zinc $(II)$ ion on reaction with $NaOH$ first gives a white precipitate which dissolves in excess of $NaOH$ due to the formation of:

The atomic radii of alkali metals $(M)$ lie in the order $Li < Na < K < Rb$,but the radii of $M^{+}$ ions in aqueous solution lie in the reverse order $Li^{+} > Na^{+} > K^{+} > Rb^{+}$. What is the reason for this reverse order (on going from $Li$ to $Rb$)?

Which of the following properties is $NOT$ an anomalous property of $Li$?

The alkali metal with the lowest $E^{\circ}_{M^{+}/M} (V)$ is $X$ and the alkali metal with the highest $E^{\circ}_{M^{+}/M} (V)$ is $Y$. Then $X$ and $Y$ are respectively:

$A$ $s$-block element $(M)$ reacts with oxygen to form an oxide of the formula $MO_{2}$. The oxide is pale yellow in colour and paramagnetic. The element $(M)$ is:

The main oxides formed on combustion of $Li, Na$ and $K$ in excess of air are,respectively: