The evidence needed to prove salt and water make a solution.
When a solution is saturated (characteristics).
What would happen to a solution when you add 1 spoon of salt to 100mL of water in a cup; 2 spoons to the same amount of water in a different cup; 3 spoons to the same amount of water in another cup; and 4 spoons of salt to the same amount of water (you will notice a large difference between 1 spoonful and 4 of salt which will help you understand how the solution differs in each cup.
How sodium chloride and Epsom salts are the same and how they are different.
Understand:
Rock candy experiment and what would cause sugar crystals to NOT grow. Also understand why sugar crystals will grow at the bottom of the glass or pot.
How to figure out how much sugar was used to saturate 150mL of water without having to redo an experiment.