Question

Density of milk is $1.04g/c{{m}^{3}}$. Therefore $1c{{m}^{3}}$ of milk has a mass of _______ g.

Answer 1

Hint: Go through the definition of density. Think whether a bucket full of iron and a bucket full of water weigh the same? Of course not, but what exactly is the difference? It is due to the virtue of the difference in their density.

Complete step-by-step answer:
Density of a substance is the measure of compactness of a substance. The definition of density is the ratio of the mass contained to its volume or the mass per unit volume.
$\text{Density}=\dfrac{\text{mass}}{\text{volume}}$
Suppose you take a bucket and fill it with water and weigh it. Then you take the same bucket and fill it with iron or cotton and weigh it again. From intuition, one can guess that the bucket full of iron will weigh more than the bucket with water, which will be more than that of the bucket filled with cotton.
But why does it happen? The volume of the items is the same. The density of the materials which is responsible for the difference in the weights.
The reason that some materials have high density and some have low, is because molecules of high-density materials are more closely packed than low density materials.
Here, in question, the density of milk is given: $1.04g/c{{m}^{3}}$. So, mass contained in $1c{{m}^{3}}$ is:
$\begin{align}
  & \text{mass}=\text{density}\times \text{volume} \\
 & \text{mass}=1.04g/c{{m}^{3}}\times 1c{{m}^{3}}=1.04g \\
\end{align}$

Note: Be careful with units and dimension conversion, here density is given in CGS, therefore check whether the volume is also in the same unit, otherwise convert it. The SI unit of density is $\dfrac{kg}{{{m}^{3}}}$. In CGS its unit is: $\dfrac{g}{c{{m}^{3}}}$.
Few methods of measuring density are: hydrometer, Hydrostatic balance and immersed body method (a buoyancy method for liquids). Density may be uniform or non-uniform depending on the substance.