In chemistry, the term physical change implies that a substance is changing form, like when water freezes to form ice. The water has not changed its identity, only its appearance from a liquid to a solid. Physical processes like shaking, hitting or even chewing can help things change their form. For example, when we chew our food, chewing (a physical process) helps us to make food easier to swallow by making it into a liquid. In this activity students will use shaking (a physical process) to transform a liquid (heavy whipping cream) into a solid.
In this activity, students will observe how physical processes like shaking can cause things to change. Materials:
Small glass jar with lid (baby food jars are the best)
Heavy whipping cream
Instructions: 1. Fill each jar about three-quarters of the way full.
2. Tightly seal each jar with its lid.
3. Shake the jar for 10-15 minutes or until the whipping cream has solidified.
How It Works: When the jar is shaken the particles are forced close together. A few particles clump together and soon, with all the shaking more and more particles clump together until most of are in a solid.
Discussion Questions to Ask: What did we add into the jar?
- What did we do to change the heavy whipping cream?
- When was the whipping cream a liquid?
- When was the whipping cream a solid?
Did you know that cooking is a chemical and a physical process? Exploring other food processes like making cheese, baking bread, even making a cake are easy ways to introduce the concept of physical and chemical changes. Chemistry is not just only in the lab or taught during science class. It is important to help young students recognize chemistry concepts inside and outside of the classroom. For more information on how to teach young students about chemical and physical change, visit: http://acswebcontent.acs.org/scienceforkids/index.html#Reactions