Which of the following does not dissolve in dil $H_2SO_4$?

$A$ metal $M$ and its compound can give the following observable changes in a sequence of reactions: $M$ $\xrightarrow{\text{dilute } HNO_3} \text{Colourless solution}$ $\xrightarrow{\text{aqueous } NaOH} \text{White precipitate}$ $\xrightarrow{\text{excess } NaOH_{(aq)}} \text{Colourless solution}$ $\xrightarrow{H_2S} \text{White precipitate}$. Identify the metal $M$.

Which of the following alloys contains a non-metal?

Which one of the following metallic hydroxides does not dissolve in sodium hydroxide solution?

$A$ mixture of sodium oxide and calcium oxide is dissolved in water and saturated with excess carbon dioxide gas. The resulting solution is ...... It contains ......... :

Which of the following substances is used as a fertilizer?