What term describes the amount of matter in an object?

• A. Mass
• B. Density
• C. Volume
• D. Weight

Answer: (A)

Mass is the amount of matter in an object. It stays the same no matter where you are because it’s a measure of how much stuff there is, not how hard gravity is pulling on it. We typically measure mass with a balance or scale using units like grams or kilograms.

Density, volume, and weight are related but different ideas. Density is how much mass is packed into a given volume (mass per volume), so you need both mass and volume to figure it out. Volume is the amount of space an object takes up. Weight is the gravitational force acting on that mass, so it can change depending on where you are in the universe (Earth, Moon, Mars). For example, a rock with a certain mass has the same mass on Earth and the Moon, but it would weigh less on the Moon because gravity is weaker there.