Bulk density

Mass density is a physical concept that tells us how much mass is present in a given volume. It is often measured in grams per cubic centimetre (g/cm³). Unlike area density, which tells us how much mass is distributed over a given area (measured in grams per square metre), mass density focuses on how compact the matter is in a given space.

Let us think, for example, of a piece of wood and a block of iron with the same volume. The mass density of the iron block will be much higher, since iron has a higher mass per unit volume than wood. This distinction between mass density and area density is important in order to better understand the properties and the behaviour of different materials.