$SiCl_4$ on hydrolysis gives:

Assertion $(A)$: The maximum covalency of $Si$ and $Ge$ is $6$ but that of carbon is $4$.
Reason $(R)$: Due to the presence of $d$-orbitals in $Si$ and $Ge$,both these elements can undergo $sp^3d^2$ hybridisation and covalency of $6$ is possible. Carbon has no $d$-orbitals in it and hence its covalency is $4$.
The correct answer is:

Among the following elements, $X$ exhibits maximum catenation and $Y$ is the least abundant on earth. $X$ and $Y$ elements are

Diamond and emerald are forms of which of the following respectively?

Of the following acids, the one which has the capability to form complex compounds and also possesses both oxidizing and reducing properties is:

Which of the following acids is formed when $SiF_4$ reacts with water?