The density of a substance is the ratio of its mass to volume.
The SI unit of density = \(\cfrac{the\,SI\,unit\,of\,mass}{the\,SI\,unit\,of\,volume}\) = kg/m3
[Note: Density is useful in determining the purity of a substance. The CGS unit of density is g/cm3 .
1 kg/m3 = 103 g/(100 cm)3 = 10-3 g/cm3
∴ 1g/cm3 = 1000 kg/m3}