Select the correct order of melting point:

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

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:

The number of six-membered carbon rings and five-membered carbon rings present in Buckminsterfullerene are $x$ and $y$ respectively. The sum of $x$ and $y$ is:

Which of the following gives $SO_2$ with dilute $H_2SO_4$?

Which of the following is an incorrect statement?