How many moles of urea are present in $5.4 \ g$? (Molar mass $= 60 \ g/mol$)

Find the number of molecules,number of carbon atoms,number of hydrogen atoms,and total number of atoms in $5.6 \ L$ of $CH_4$ at $STP$.

The number of molecules and atoms present in $7.1 \ g$ of chlorine gas $(Cl_2)$ are respectively:

Which of the following contains the maximum number of oxygen atoms?

Number of molecules in $100 \ mL$ of each of $O_2$,$NH_3$,and $CO_2$ at $STP$ are

Three $1 \ L$ flasks contain $N_2$,$Ne$,and $O_3$ gases respectively. At the same temperature and pressure,find the ratio of the total number of atoms present.