What does density look like?

Density is a measure of how much mass is contained in a given volume. It can be visualized as the concentration of particles in a substance; for example, a dense material like lead appears compact and heavy for its size, while a less dense material like foam feels light and airy. In liquids, density differences can be seen when oil floats on water, illustrating that oil is less dense than water. Overall, density affects how substances interact, such as whether they sink or float in a fluid.