Final answer:
The property that remains constant in the solid, liquid, or gas state is mass, which is the total quantity of matter in an object and does not change with a change in state. Yet, in all these transformations, the total mass remains constant. Therefore, the correct answer is a) Mass.
Step-by-step explanation:
When considering the different states of matter—solid, liquid, and gas—the property that remains constant is mass. Irrespective of whether a substance is in a solid, liquid, or gas state, its mass does not change. This is because mass is a measure of the total quantity of matter in an object, and changing the state of a substance (for example, from liquid water to steam) does not alter the amount of matter. While other properties like volume, shape, and temperature may vary with the state of matter, the mass remains unaffected. For example, a solid has a definite shape and volume, a liquid has a definite volume but takes the shape of its container, and a gas has neither a definite shape nor volume. Yet, in all these transformations, the total mass remains constant. Therefore, the correct answer is a) Mass.