The density of ice is $0.921gc{m}^{-3}$ . Calculate the mass of a cubic block of ice which is $76\mathrm{mm}$ on each side. 

Two molecules of hydrogen and one molecule of oxygen make form the material known as water. It is the most crucial component. It may be found in solid, liquid, and gaseous phases. Mass per volume of a material is a measure of density.

To calculate mass from density, the following formula can be used.

$\mathrm{density}=\frac{\mathrm{mass}}{\mathrm{volume}}$

$\Rightarrow \mathrm{mass}=\mathrm{density}\times \mathrm{volume}$

Volume of cube is calculated as;

$\mathrm{V}={\mathrm{a}}^3$

Where a is the side of cube.
Given;$\mathrm{density}=0.921 {\mathrm{gcm}}^{-3}$

$\mathrm{a}=76 \mathrm{mm}=7.6 \mathrm{cm}$

Therefore, 

$\mathrm{m}=0.921\times {(7.6)}^3=0.921\times 438.98=404\approx 4\times {10}^2 \mathrm{g}$.

So, the correct answer is option (B).