The basic structural unit of silicates is

Identify the cyclic silicate ion given in the figure below:

Identify the incorrect statements from the following:
$I.$ Tin in $+2$ state acts as a reducing agent,while lead in $+4$ state acts as a strong oxidising agent.
$II.$ Silicon exists as both $[SiF_6]^{2-}$ and $[SiCl_6]^{2-}$ forms.
$III.$ The hybridisation of carbon in fullerene is $sp^3$.
$IV.$ Among $Ge$,$Sn$,and $Pb$,the lowest melting point is for $Sn$.

The correct order of catenation is

Which set of elements form electron precise hydrides?

How many compounds can be formed when carbon combines with oxygen?