Which of the following forms of carbon is isomorphous with crystalline silicon?

Which of the following is a mixed oxide?

Which of the following oxidation states are the most characteristic for lead and tin respectively?

Philosopher's wool when heated with $BaO$ at $1100\,^{\circ}C$ gives a compound. Identify the compound.

Which gas is used in aerated water?

Reaction of an inorganic sulphite $X$ with dilute $H_{2}SO_{4}$ generates compound $Y$. Reaction of $Y$ with $NaOH$ gives $X$. Further,the reaction of $X$ with $Y$ and water affords compound $Z$. $Y$ and $Z$,respectively,are: