Presentation on theme: "What is a chemical equation?"— Presentation transcript:
1What is a chemical equation? Lesson 30What is a chemical equation?
2When you tear a piece of paper into tiny pieces, you still have paper, right? No chemical changes have been made to the paper, only physical changes.No new properties were made. The paper has the same chemical makeup.
3A change like tearing paper is called a physical change. Physical change is when there is a change in the appearance only. The chemical makeup of the matter is exactly the same.
4What happens if you burn paper? You no longer have paper.Paper is a compound made up mostly of carbon and hydrogen.
5When paper burns, it links up with oxygen from the air When paper burns, it links up with oxygen from the air. Three products form: ash, water, and carbon dioxide.When paper burns, there is a change in the way atoms link together. New products form, and properties change.
6A change like burning paper is called a chemical change. In a chemical change, the chemical makeup of a substance changes.New products are formed, properties change.