Introduction to Chemical Reactions: physical and chemical changes CLASS NOTES

Elements and Compounds An element is a substance that contains only ____ kind of atom Compound is a pure substance that is made of up ______ or more elements Elements and compounds are created through bonding What are the two different types of bonding? Today we will learn about how the combination of these elements and compounds can create chemical reactions!

Chemical reactions produce changes… TWO types of changes: physical and chemical Physical change: Change in state: solid, liquid or gas May change in colour Chemical change: forms a new substance Heat may be produced For example: newspaper physical change: can make a ball of newspaper chemical change: sun’s energy can turn the paper yellow is you leave it in the sun

Physical or Chemical Change? Butter melting Digestion of foods in your body Bubbles of gas escaping from a soda Rust on a car Lake freezing (turning to ice from water)