Which expression correctly represents density?

Which expression correctly represents density?

• A. mass/volume
• B. volume/mass
• C. mass×volume
• D. density equals weight

Answer: (A)

Density tells us how much matter is packed into a given space, so it is defined as mass per unit volume. The expression that matches this idea is mass divided by volume. When you have more mass in the same volume, the density increases; when you increase the volume without increasing mass, the density decreases. If you take volume divided by mass, you’re looking at the inverse relationship (specific volume), which is not density. Multiplying mass by volume doesn’t align with the density concept at all. And saying density equals weight mixes in gravity—weight depends on gravity, whereas density is the mass per volume and uses mass, not weight, in its definition.

Density tells us how much matter is packed into a given space, so it is defined as mass per unit volume. The expression that matches this idea is mass divided by volume. When you have more mass in the same volume, the density increases; when you increase the volume without increasing mass, the density decreases.

If you take volume divided by mass, you’re looking at the inverse relationship (specific volume), which is not density. Multiplying mass by volume doesn’t align with the density concept at all. And saying density equals weight mixes in gravity—weight depends on gravity, whereas density is the mass per volume and uses mass, not weight, in its definition.