What is the number of moles of sulfur atoms present in $n$ mole molecules of mustard gas?

Assertion $(A)$: Equal moles of different substances contain the same number of constituent particles.
Reason $(R)$: Equal weights of different substances contain the same number of constituent particles.
The correct answer is

If $10^{21}$ molecules are removed from $200 \ mg$ of $CO_2$,then the number of moles of $CO_2$ left are .......... $\times 10^{-3}$.

The number of molecules in $16 \ g$ of methane is ...... $\times 10^{23}$.

$5.6 \, L$ of oxygen at $STP$ contains .............

If $10^{21}$ molecules are removed from $200 \ mg$ of $CO_2$,how many moles of $CO_2$ will remain?