Dry bleaching is done by

Which of the following species is not stable?

$P_4 + NaOH + H_2O \to x + y$; find the sum of total $P-H$ bonds in $x$ and $y$.

Which of the following is a three dimensional silicate?

In which one of the following pairs,both oxides are acidic?

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: