Which property remains unchanged when the amount of matter changes for a pure substance?

Which property remains unchanged when the amount of matter changes for a pure substance?

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

Answer: (A)

When we think about properties, some depend on how much substance you have (extensive properties) and some do not (intensive properties). Mass and volume grow or shrink with the amount of matter. But color is an intrinsic property of the material, determined by its composition and how it interacts with light, so it stays the same regardless of how much you have—as long as the substance is pure and conditions are the same. That’s why color remains unchanged when you change the amount of matter.

When we think about properties, some depend on how much substance you have (extensive properties) and some do not (intensive properties). Mass and volume grow or shrink with the amount of matter. But color is an intrinsic property of the material, determined by its composition and how it interacts with light, so it stays the same regardless of how much you have—as long as the substance is pure and conditions are the same. That’s why color remains unchanged when you change the amount of matter.