Which of the following oxides is amphoteric in character?

Explain the reactivity of group $14$ elements towards oxygen.

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

The compound that is used in smoke screens is

Match List-$I$ with List-$II$.

List-$I$ (Si-Compounds)	List-$II$ (Si-Polymeric/other products)
$A$. $(CH_3)_4 Si$	$I$. Chain silicone
$B$. $(CH_3) Si(OH)_3$	$II$. Dimeric silicone
$C$. $(CH_3)_2 Si(OH)_2$	$III$. Silane
$D$. $(CH_3)_3 Si(OH)$	$IV$. $2D$-Silicone

Choose the correct answer from the options given below:

Identify the correct statement$(s)$ from the following: $I$. The catenation property of group $14$ elements decreases from carbon to tin. $II$. Fullerene $(C_{60})$ has $20$ five-membered carbon rings and $12$ six-membered carbon rings. $III$. $SiO_2$ is soluble in conc. $NaOH$.