Science Lesson Plan: Identifying Chemical Changes

Illinois State Standards:

11.A.3f Interpret and represent results of an analysis to produce findings

12.C.3a Explain interactions of energy with matter including changes of state and conservation of mass and energy.

1.B.3a Preview reading materials, make predictions, and relate reading to information from other sources. Process-oriented Objective: Students will be able to:

- Explain what a chemical change is

- List chemical properties of common materials

- Explain how chemical changes affect their lives

- Demonstrate an awareness of the potential dangers of chemical changes

What do I want students to discover?: That chemical changes occur constantly every day, constantly creating new substances from the combinations of other substances.

Introduction activity / Initial discussion:

Take a 35mm film canister (clear works best) and fill it halfway with water. Put in an Alka-Seltzer tablet, firmly affix the cap, and then stand back. The resulting explosion is a great way to lead into the subject of chemical reactions and what can occur in a chemical reaction.

Materials Needed:

1) Iodine

2) Alcohol

3) Starch

4) Iron Nail

5) Yeast

6) Sugar

7) Milk

8) Water

9) Vinegar

10) Bread

11) Toaster

12) Hot Plate

13) Small Sauce Pan

Description of Activities:

Have the students make a chart with one column for the first material, one column for the material to be mixed, and a third column to record results. Students will then combine pairs of these items (using the toaster, hot plate, and sauce pan to create some of the reactions) and record what they see.

Typical Questions Discussed:

What do you think will happen if you combine these two substances?

What do you think is happening to these substances?

What is happening when you apply heat to certain substances?

Are the substances changing?

Are new substances being created?

How children will be encouraged to investigate on their own in the classroom:

Having a large collection of substances for the students to mix and observe results is a good way to keep students interested in investigation chemical reactions on their own. Plus, the freedom of choosing their own combinations of materials gives the student a level of ownership (obviously the teacher should make sure that no potentially hazardous combinations are possible.

Expected Conclusions:

The mixing of certain substances causes a chemical change where one or both substances are changed and new substances are created. The students should also grasp the idea that chemical changes are occurring constantly around them even though they may not see many of them.

Applications to real life situations:

Chemical changes can not be avoided. Almost everything we do with our bodies results in a chemical change. Taking aspirin causes a chemical change. The cereal you ate for breakfast is causing a chemical change. Even breathing is causing chemical changes. This activity should make it abundantly clear that chemical changes are a regular part of everyday life.