The largest number of molecules are in:

How many molecules are present in $22400 \ cm^3$ of a gas at $STP$?

Among the following,choose the ones with an equal number of atoms.
$A$. $212 \ g$ of $Na_2CO_3(s)$ [molar mass $= 106 \ g/mol$]
$B$. $248 \ g$ of $Na_2O(s)$ [molar mass $= 62 \ g/mol$]
$C$. $240 \ g$ of $NaOH(s)$ [molar mass $= 40 \ g/mol$]
$D$. $12 \ g$ of $H_2(g)$ [molar mass $= 2 \ g/mol$]
$E$. $220 \ g$ of $CO_2(g)$ [molar mass $= 44 \ g/mol$]
Choose the correct answer from the options given below.

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

How many moles of nitrogen atoms are present in $8 \ g$ of ammonium nitrate (in $mol$)?

Find the number of moles present in $0.448 \ L$ of dihydrogen at $STP$. (in $mol$)