Can you give an example of a physical change?
Can you give an example of a chemical change?
Chemical changes involve the breakdown or building up of molecules. Physical changes affect the form of a substance without changing its molecular composition. Examples of physical changes include melting, freezing, and boiling.
Chemical and Physical Changes
Chemical Change: A change that alters the structure of a chemical substance, resulting in a new substance. Physical Change: A change in the state or properties of a material that does not involve a change in the chemical composition. Molecular Composition: The elements that make up a substance and the way they are connected to each other.
Which of these best describes a chemical change?
- The appearance of the substance changes
- The energy of the substance changes
- The composition of the substance changes
- None of the above
When water boils, it changes from a liquid to a gas - this is an example of a physical change. When sugar is dissolved in water, it undergoes a chemical change. When an egg is cooked, it undergoes both physical and chemical changes!
Draw / write: How are chemical and physical changes different?
Draw / write: What are some examples of physical and chemical changes?
What do you think is the most important thing to remember when distinguishing between chemical and physical changes?
How does observing physical and chemical changes help us better understand the world around us?