Density

Different substances have different amounts of matter packed into the same volume.

[definition: The density of a substance is the mass per unit volume of a substance.

density = Mass/Volume]

The S.I. unit for mass and volume are the kilogram (kg) and the cubic metre (m³ ) respectively. Hence, the S.I. unit of density is kg/m³ . Another common unit for density is g/cm³

^{Floating and sinking}

^{In general, a denser substance will sink while a less dense substance will float.}

^{For example, the green substance in the picture is the least dense. The blue substance is denser than the green substance but less dense than the red and yellow substances. The red substance is denser than the green and blue substances but not the yellow substance. The yellow substance is the densest of them all.}

Source: Lower Secondary Science Matters

published by Marshall Cavendish Education