All phases of matter may have a fixed mass

Solids have a fixed mass, volume, and shape. Solids have a fixed mass, volume, and shape. All phases of matter may have a fixed (definite) mass.

 You might have seen this when you pulled a plant such as a weed or vegetable out of the ground and a clump of soil clung to its roots. Plants also help absorb some of the water in the soil. These effects make it harder for water to wash the soil away.