Learn how to find out the difference between tap water and spring water. Material processes - Separating mixtures - Separation by evaporation Learning Points Evaporation can be used to separate a solution. A solution is formed when a soluble substance dissolves into a liquid. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.