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.

To find the volume of an objects like a cube or a box, measure the length × width × height. If measured in centimeters, the answer will be in cubic centimeters (cm³). Mass is measured in grams. The ...

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 ...

Save guides, add subjects and pick up where you left off with your BBC account. It is true however to say that metal is denser than air, and so for equal volumes of metal and air then the metal ...

It is tempting to think that some materials are always heavier than other materials. For example, someone might say that metal is heavier than air. But it depends on how much of each material ...