If something seems light for its size (like a bag of cotton or pumice rock), then we say it has low density. Mass is the amount of matter in an object. Volume is how much space the object takes up.

Note: We are purposely using the terms “size” and “amount” instead of “volume” in discussions of density. We are also using “heavy”, “light”, and “weight” instead of “mass”. If your students have ...

The units of density depend on the units used for mass and volume. The most commonly used units are grams per cubic centimetre (g/cm³) or kilograms per cubic metre (kg/m³). These balloons are ...

Note: We are purposely using the terms “size” and “amount” instead of “volume” in this lesson about density. We are also using “heavy”, “light”, and “weight” instead of “mass”. If your students have ...

Density and dispersion are two descriptors of populations that can provide insight into processes such as competition and territoriality. Their measurement is therefore fundamental to our ...