Which of the following is used for making optical instruments?

The number of amphoteric oxides from the following is
$CO_2, GeO_2, SnO_2, PbO_2, CO, GeO, SnO, PbO$

What is the increasing order of stability of dihalides of $Si$,$Ge$,$Sn$,and $Pb$?

The hybridisation of elements present in fullerene and graphite are respectively.

With respect to graphite and diamond,which of the statement$(s)$ given below is (are) correct?
$(A)$ Graphite is harder than diamond.
$(B)$ Graphite has higher electrical conductivity than diamond.
$(C)$ Graphite has higher thermal conductivity than diamond.
$(D)$ Graphite has higher $C-C$ bond order than diamond.

In the following reaction,identify the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$:
$\underline{S}_8 + H_2O \longrightarrow$ No reaction