# How come you cannot use mass or volume alone to identify substances?

Mar 1, 2016

Mass and volume are extrinsic properties.

#### Explanation:

For Example

A pail may contain water that is $1 \text{kg}$ in mass and $1 \text{L}$ in volume.

A drop of water may be $1 \text{g}$ in mass and $1 \text{mL}$ in volume.

Both are water, but they have different mass and volumes. Therefore you can't identify whether a substance is water just by measuring its mass and volume.

However, the ratio of the mass to volume (density) can be used to identify substances.