Working through the properties of each state of matter. On the MAP test students will have to be able to describe and compare properties of matter. Being able to find attributes of objects and sort other objects according to their attributes. One and more than one attribute are usually involved.
Teachers usually have the students sort objects by using the five senses.
I would suggest you put the chocolate in a baggie first. These are just a few suggestions if you need more sources, let me know. I can give you other activities, but this should get you started. Physical Science has activities for Solids, Liquids and Gases. Working through the properties of each state of matter.