Mass is measured with a balance.
The legal unit of mass is the kilogram (kg).
The gram (g) is also used.
We note: m = 50 g
(The mass is equal to 50 grams.)
Volume is measured with a graduated cylinder.
The legal unit of volume is the cubic meter (m3).
The liter (L), milliliter (mL), or cubic centimeter (cm3) are also used.
We note: V = 100 mL
(The volume is equal to 100 milliliters).
The density ρ of a liquid in g/L indicates the mass in grams of one liter of that liquid.
Example:
The density of alcohol is equal to 789 g/L, so the mass of one liter of alcohol is equal to 789 g.
Density is equal to the ratio of mass to volume.
The legal unit is the kilogram per cubic meter (kg/m3).
The g/L or g/cm3 are also used.
With m in grams (g) and V in liters (L), we obtain ρ in g/L.