Which of the following is a volatile salt that undergoes sublimation?

An oxide of an element is a gas and dissolves in water to give an acidic solution. The element belongs to:

The catenation tendency of $C$,$Si$ and $Ge$ is in the order $Ge < Si < C$. The bond energies (in $kJ \ mol^{-1}$) of $C-C$,$Si-Si$ and $Ge-Ge$ bonds,respectively,are:

Explain fullerenes.

Nitrolim is

Name the type of the structure of silicate in which one oxygen atom of $[SiO_4]^{4-}$ is shared?