Density

Definition of density

What is density? Density is defined as the amount of mass in a unit volume of the substance.

What is the formula for density? 

Density = mass ÷ volume

The density of water

The density of water is 1.00 g/cm³. The gram in the density of water was originally defined as the mass of 1 cm³ of water at a specific temperature. The SI unit used for water density is g/cm³ instead of the usual SI unit kg/m³.

Other densities of common substances

• The density of air is 0.001 g/cm³
• The density of Balsa wood is 0.16 g/cm³
• The density of water is 1 g/cm³
• The density of table salt is 2.16 g/cm³
• The density of iron is 7.9 g/cm³
• The density of gold is 19.32 g/cm³

Density and weight

Density and weight are sometimes confused. A person who says that iron weights more than air generally means that iron has a higher density than air. 1 kg of air has the same mass as 1kg as iron but iron is confined to a smaller volume than air making iron have higher density than air.