The highest number of helium atoms is in

Number of atoms in the following samples of substances is largest in

From the following,the largest number of atoms are in

Find the number of moles of sodium atoms in $6.9 \times 10^{-2} \ kg$ (Atomic mass $= 23 \ g \ mol^{-1}$)

The number of water molecules in $250\, mL$ of water is closest to $.....\, \times 10^{23}$.
[Given: density of water is $1.0\, g\, mL^{-1}$; Avogadro's number $= 6.023 \times 10^{23}$]

Number of moles and number of molecules in $1.4187 \ L$ of $SO_2$ at $STP$ respectively are: