By definition,Solubility is the maximum amount of solute that can be dissolved in 100 g of water.
A solution is called saturated solution when the concentration of solute becomes equal to its solubility.
If the concentration of solute is less than solubility it is called unsaturated solution.
In this case: solubility is 26.2 grams.
If we dissolve 26 grams of Epsom salt in 100 g of water , concentration of solute is less than the solubility(26.2 g in 100 g of water) , hence it is an unsaturated solution.
When water reaches its boiling point and turns into water vapor, the molecular structure of water remains the same. It is only the state of the substance that is changed in this process. I hope this helps you
