Dilution refers to decreasing the ratio of total solution to the reference solution by the addition of other liquids. By adding water to tomato soup, the balance of “tomato soup” molecules decreases from 100% tomato soup, to eventually 1:1 TS and Water (50%), and so on. Chemically, you can observe this as decreasing the concentration of tomato soup in this solution.
pure substances can be divided into two groups; elements and compounds