The density of a substance is the ratio of its ________ and volume.

1. Density is defined as mass per unit volume.
2. Density of an object can be defined as the mass of an object in a given volume.
3. Density is the property of an object which depicts the amount of matter in the given volume.

$Density\left(D\right)=\frac{Mass\left(M\right)}{Volume\left(V\right)}$

Hence, The density of a substance is the ratio of its mass and volume.