Which of the following anions is present in the chain structure of silicates?

Who discovered the allotrope of carbon known as fullerene?

Match the following:

List-$I$ (Compound)	List-$II$ (Silicate)
$A$. Zircon $(ZrSiO_4)$	$P$. Ring/Cyclic
$B$. Talc $(Mg_3(OH)_2(Si_2O_5)_2)$	$Q$. Ortho
$C$. Thortveitite $(Sc_2Si_2O_7)$	$R$. Pyro
$D$. Benitoite $(BaTiSi_3O_9)$	$S$. Sheet

The element whose hydride contains the maximum number of hydrogen atoms per atom of the element is

It is observed that $Pb^{2+}$ is more stable than $Pb^{4+}$, while $Sn^{2+}$ is less stable than $Sn^{4+}$. Consider the following reactions:
$PbO_{2} + Pb \rightarrow 2PbO; \Delta_{r}G^{\circ} (1)$
$SnO_{2} + Sn \rightarrow 2SnO; \Delta_{r}G^{\circ} (2)$
Identify the correct set from the following.

The least stable hydride is: