The property of a solution which remain the same after it is diluted is THE AMOUNT OF SOLUTE. Dilution is the process of adding solvent to a solution. This action decreases the concentration of the solute in the solution. When a solution is diluted, the amount of solvent increase, the total volume increases, the concentration decreases, but the amount of solute stays the same.
the solute is the one that dissolves meaning its particles are separating into the solvent, and the solvent is the one that dissolves the other substance.