A 20.0 g pure sample of Li2O(s) contains 46.5% Li by mass. A 10.0g pure sample of Li2S(s) is mixed into that 20.0 g pure sample of Li2O(s). Which of the following statements identifies what happened to the mass percent of lithium in the final mixture, when compared to a pure sample of Li2O(s), with a correct justification?