So therefore, let's look at what happens to our surface area after we add this substance. The surface area of the liquid is constant, it remains the same. And that's because our system, our container, remains constant. It will not change in shape or size. So if you take the crosssectional before addition and after addition, the crosssectional area will remain the same. What will change however, is the number of pure liquid molecules found on the surface area and this number will decrease.