Here's why:
* Equilibrium: This means that the rate of dissolution (solute dissolving into the solvent) is equal to the rate of crystallization (solute coming out of solution and forming solid crystals).
* Saturated: This means that the solution holds the maximum amount of solute that it can dissolve at a given temperature and pressure.
In a saturated solution, adding more solute won't cause any more to dissolve. The extra solute will simply remain undissolved at the bottom of the container.
