Silicon dioxide is formed by the reaction of:

Which one of the following is used to convert sunlight into electricity in photovoltaic material?

The group $14$ elements $A$ and $B$ have the first ionisation enthalpy values of $708$ and $715 \ kJ \ mol^{-1}$ respectively. These values are the lowest among their group members. The nature of their ions $A^{2+}$ and $B^{4+}$ respectively is:

Which of the following elements shows a stable $+2$ oxidation state?

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

$Na_2CO_3$ reacts with $SO_2$ in an alkaline medium to form: