The $[SiO_4]^{4-}$ unit has a tetrahedral structure. Which silicate is formed by sharing three oxygen atoms per $[SiO_4]^{4-}$ unit?

$A$ tetravalent element forms monoxide and dioxide with oxygen. When air is passed over the heated element $(1273 \ K)$,producer gas is obtained. The monoxide of the element is a powerful reducing agent and reduces ferric oxide to iron. Identify the element and write the formulas of its monoxide and dioxide. Write chemical equations for the formation of producer gas and the reduction of ferric oxide with the monoxide.

Rationalise the given statements and give chemical reactions:
$1$. Lead $(II)$ chloride reacts with $Cl_2$ to give $PbCl_4$.
$2$. Lead $(IV)$ chloride is highly unstable towards heat.
$3$. Lead is known not to form an iodide,$PbI_4$.

In the carbon family,elements other than carbon do not form $p\pi - p\pi$ bonds because their atomic radii are very ........

Which of the following halides cannot be hydrolysed?

Which of the following is known as silicone?