Which term refers to the property that measures how dense a material is, mass per unit volume?

• A. Conductivity
• B. Density
• C. Volume
• D. Solubility

Answer: (B)

Density is the property that measures how much matter is packed into a given amount of space, expressed as mass per unit volume. Think of it as how tightly the material’s particles are packed together. When the same volume holds more mass, the material is denser; when it holds less mass, it’s less dense. Common units are grams per cubic centimeter (g/cm^3) or kilograms per cubic meter (kg/m^3).

This explains everyday observations like why a metal block feels heavier than a wooden block of the same size—the metal has a higher density because more mass fits into the same volume. By contrast, volume describes how much space an object occupies, not how much matter is packed inside. Conductivity is about how well a material transfers heat or electricity. Solubility is about how much of a substance can dissolve in a solvent.