The hybridisation of the central atom and the shape of $[IO_2F_5]^{2-}$ ion,respectively are

Consider the following statements for $\dot{CH_3} = X$ and $\dot{CF_3} = Y$:
$I$. When $X$ dimerises,the bond angle decreases.
$II$. When $X$ dimerises,the bond angle increases.
$III$. In the $X-Y$ molecule,the $C-C$ bond length is less than that in the $Y-Y$ molecule.
$IV$. The bond angle in $X$ is greater than that in $Y$.

In which hybridisation is an angular shape not possible?

The hybridisation of the central iodine atom in $IF_5$,$I_3^-$,and $I_3^+$ are respectively:

The structure of $IF_{7}$ is

Hybridisation state of $C$ in diamond is