The mass of a sample of aluminum is $54 \ g$. The mass of the same number of magnesium atoms will be ......... $g$.

Which of the following contains $6.02 \times 10^{22}$ molecules?

What is the volume occupied by $1$ molecule of water, if its density is $1 \,g \,cm^{-3}$?

If $N_A$ is Avogadro’s number,then the number of valence electrons in $4.2 \ g$ of nitride ions $(N^{3 -})$ is ................... $N_A$.

If $3.01 \times 10^{20}$ molecules are removed from $98 \ mg$ of $H_2SO_4$,then the number of moles of $H_2SO_4$ left are:

The number of moles of water present in a spherical water droplet of radius $1.0 \ cm$ is,(Given: Density of water in the droplet $= 1.0 \ g \ cm^{-3}$)