Which of the following alloys contains a non-metal?

White vitriol is .......

Match the following substances in List-$I$ with their uses in List-$II$:
| List-$I$ (Substance) | List-$II$ (Use) |
| :--- | :--- |
| $(A)$ $Na_2O_2$ | $(I)$ Photoelectric cells |
| $(B)$ $D_2O$ | $(II)$ Antacid |
| $(C)$ $Cs$ | $(III)$ Oxidising agent |
| $(D)$ $Mg(OH)_2$ | $(IV)$ Moderator |

Identify the elements of alkali metals and alkaline earth metals respectively having the highest $1^{st}$ ionization enthalpy.

Match the following compounds in Column-$I$ with their products of heating effect in Column-$II$:

Column-$I$ (Compound)	Column-$II$ (Products of heating effect)
$a$. $LiNO_3$	$P$. Metal oxide
$b$. $FeSO_4 \cdot 7H_2O$	$Q$. Paramagnetic gas
$c$. $NaHCO_3$	$R$. Acidic gas
$d$. $BeCO_3$	$S$. Evolved gas has same number of $\sigma$ and $\pi$ bonds

What are the products formed when $AgNO_3$ is heated strongly?