Which property increases with more matter when the substance is unchanged?

• A. Mass
• B. Colour
• C. Density
• D. Boiling Point

Answer: (A)

Mass is the property that increases with more matter because it directly measures how much stuff there is. If you have more of the same substance, you’ve added more matter, so the mass goes up. Other properties don’t follow this same rule: color depends on light interaction and usually doesn’t change just because you have more material, provided the material is the same; boiling point is set by the substance and the pressure, not by how much you have, so it stays the same; density is a ratio of mass to volume, and for a uniform material at a given temperature and pressure it stays the same even if you add more, unless you change the volume. So the amount of material specifically causes mass to increase.