The SI unit of density is kilograms per cubic meter (kg/m³). This means that density is expressed as the mass in kilograms of a substance occupying a volume of one cubic meter.
Understanding Density and its Units
Density (ρ) is a fundamental physical property of matter, defined as the mass (m) of a substance per unit volume (V):
ρ = m/V
Different units can be used to express density, depending on the context and the scale of measurement. While kg/m³ is the standard SI unit, other common units include:
- g/cm³: Grams per cubic centimeter, frequently used in chemistry and material science.
- g/mL: Grams per milliliter, equivalent to g/cm³ and commonly used for liquids.
- kg/L: Kilograms per liter, another convenient unit for liquids.
- t/m³: Tonnes per cubic meter, used for larger-scale applications.
Several sources confirm the SI unit of density:
- Byjus.com: Multiple pages on Byjus.com explicitly state that the SI unit of density is kg/m³.
- Socratic.org: This platform clarifies that the derived SI unit for density is kg/m³.
- Chegg.com: A solved example on Chegg.com correctly identifies kg/m³ as the SI unit.
- Wikipedia: While listing several units, Wikipedia confirms that kilogram per cubic meter (kg/m³) is the SI unit.
- Chemistry LibreTexts: The LibreTexts explicitly state that the SI unit for density is kg/m³.
The choice of unit often depends on the application. For instance, while kg/m³ is suitable for large-scale engineering projects, g/cm³ or g/mL might be more practical when dealing with small samples in a laboratory setting. Regardless of the unit used, the underlying principle of mass per unit volume remains constant.
