What is the value of $\angle S-S-S$ in the puckered $S_8$ ring of rhombic sulfur (in $^{\circ}$)?

Which of the following is a suboxide?

The silicate anion in the mineral kinoite is a chain of three $SiO_4$ tetrahedra,that share corners with adjacent tetrahedra. The charge of the silicate anion is

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 $Sn$.

In atomic reactors,graphite is used as a

Give one method for industrial preparation and one for laboratory preparation of $CO$ and $CO_{2}$ each.