Question

Equal masses of different substances have___ volumes.

Answer 1

1. The densities of different substances are different.
   $Density\left(\rho \right)=\frac{mass\left(m\right)}{volume\left(v\right)}$
2. Because the arrangement of molecules is different in different substances.
3. Hence, having the different densities mass contained per unit volume will be different.

So, Equal masses of different substances have different volumes.