Ch. 11Lesson 3What are chemical

changes in matter?

chemical change

•one kind of matter changes into a different kind of matter

•makes new substances

Sugar and sulfuric acid chemical change

chemical change

•usually cannot be changed back to the original kind of matter

Physical change vs. chemical change

chemical change

•some happen quickly

Fast Chemical Reactions [00:44]

chemical change

•some happen slowly

Slow Chemical Changes in Matter [01:10]

examples of chemical changes

1. baking bread

examples of chemical changes

2. burning wood

examples of chemical changes

3. iron rusting

examples of chemical changes

4. cooking eggs

examples of chemical changes

5. fireworks

examples of chemical changes

6. using a battery

examples of chemical changes

7. digesting food

examples of chemical changes

8. baking a cake

Review time

How do you know burning wood is a chemical change?

•When the wood burns, the wood changes to gases and ashes. The gases and ashes are a different kind of matter.

How do you know baked bread has undergone a chemical change?

•The ingredients cannot be changed back to their original form.

What is an example of a slow chemical change?

•rusting iron

What is an example of a fast chemical change?

•burning wood

How is a chemical change different from a physical change?

•Chemical changes produce new kinds of matter, but physical changes do not.

When does your body produce chemical changes?

•When it breaks down food for energy and growth.

• wood chemical change ashes