The structure of silicates in which three oxygen atoms of $[SiO_4]^{4-}$ are shared is known as:

Which one of the following statements is not correct?

Which of the following statements are correct?
$I)$ $SnF_4$ is ionic in nature.
$II)$ Stability of dihalides of group $14$ elements increases down the group.
$III)$ $GeCl_2$ is more stable than $GeCl_4$.

Give reasons:
$(i)$ Conc. $HNO_3$ can be transported in aluminium container.
$(ii)$ $A$ mixture of dilute $NaOH$ and aluminium pieces is used to open drain.
$(iii)$ Graphite is used as lubricant.
$(iv)$ Diamond is used as an abrasive.
$(v)$ Aluminium alloys are used to make aircraft body.
$(vi)$ Aluminium utensils should not be kept in water overnight.
$(vii)$ Aluminium wire is used to make transmission cables.

The group $14$ elements $A$ and $B$ have the first ionisation enthalpy values of $708$ and $715 \ kJ \ mol^{-1}$ respectively. These values are the lowest among their group members. The nature of their ions $A^{2+}$ and $B^{4+}$ respectively is:

Choose the $INCORRECT$ statement.