$Cs^{+}$ ions impart violet colour to Bunsen flame. This is due to the fact that the emitted radiations are of

Hydrogen is not obtained when zinc reacts with

List-$I$ Elements	List-$II$ Colour imparted to the flame
$A$. $K$	$i$. Violet
$B$. $Ca$	$ii$. Brick Red
$C$. $Sr$	$iii$. Crimson Red
$D$. $Ba$	$iv$. Apple Green

Choose the correct answer from the options given below:

Which metals upon heating in the presence of air followed by hydrolysis give ammonia?

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 $Rb$)?

When carbon monoxide is passed over solid caustic soda heated to $200^{\circ} C$,it forms