Final answer:
When water is added to a sand-salt mixture, the sand remains undissolved and typically settles, while the salt dissolves, creating a homogeneous mixture until the point of saturation is reached.
Step-by-step explanation:
When water is added to the sand-salt mixture, the salt dissolves. In this scenario, the table salt (NaCl) is the solute which readily dissolves in water due to the interaction between the water molecules and the individual ions of the salt. While the salt dissolves, the sand remains undissolved and typically settles at the bottom. This forms a homogeneous mixture, as the saltwater solution becomes evenly distributed throughout the liquid. If salt is continually added to the point of saturation, the point will be reached where no more salt can dissolve. At this state, the rate of dissolution and the rate of recrystallization are equal, resulting in what is known as solution equilibrium.