I want the students to understand that everything, even foods exist in three phases or states, solid, liquid or gas. As chefs in the kitchen we usually work with foods in a solid or liquid state. We often mix liquid and solid ingredients, or multiple solid ingredients, or multiple liquid ingredients together to create some type of edible food dish. The heating or cooling of ingredients helps to further the transformations that occur when ingredients are mixed. As the temperature of a food is raised or lowered the effects are often permanent or irreversible, such as baking a cake, all the ingredients are unable to be converted back to their original states. However, there are very few recipes that are reversible, such as making an ice pop, you can leave the ice pop out on a counter and it will transform into juice again.
In each of the phases, the molecules are constantly moving. The bonds of a gas are weaker than a solid or liquid, but a solid's bonds are the strongest amongst the three phases. During the heating or cooling process it is the bonds that are manipulated that change the phase of the food. The bonds between the molecules help us to distinguish between each of the phases.