Physical and Chemical Changes
A lesson and worksheet about the difference between physical and chemical changes and how chemical reactions are described.
• Students will be able to distinguish between physical changes and chemical changes.
• Students will be able to describe what happens when substances react and undergo chemical changes.
• Students will be able to identify a chemical equation and state what it represents.
• Students will be able to recognize some of the signs of chemical changes.
5th Grade - 6th Grade - 7th Grade
Print the reading comprehension worksheet passage and questions (see below).
Students should read the passage silently, then answer the questions. Teachers may also use the text as part of a classroom lesson plan.
Matter changes all the time. There are two types of changes that matter can undergo: physical changes and chemical changes. When matter changes from one state to another, but keeps its identity it undergoes a physical change. For example, when liquid water freezes and becomes ice, it changes physically, but it is still water.
When matter undergoes a chemical change, one or more completely new compounds are formed. The atoms between chemicals link together in new ways to create new substances. An example of a chemical change is the reaction between baking soda and vinegar. If you mix these two substances together, you will notice that gas bubbles form. A chemical reaction is occurring. The bonds in the baking soda and vinegar atoms are broken and new bonds form. The result is three entirely new substances: water, carbon dioxide and sodium acetate.
Print this printable worksheet for this lesson: