Lesson 1: Invisible Matter

Wrapping Up

Conclusion

Go back and consider the questions that you answered on your activity sheet. Keep in mind the essential question from the beginning of the lesson, "How do we know that all matter is made of smaller, 'invisible' parts?" What is it about the activity that gives you evidence that water, and other types of matter, are made up of particles that cannot be seen with the naked eye? Keep this answer in mind as we progress through the remainder of this unit. What evidence were you able to collect that supports that matter is not lost when it changes from a liquid to a gas? (HINT: Consider the mass of the water before and after it was heated.)

Parent Note

Activity 1 in this lesson had the goal of indirectly introducing one of the laws of matter to your child. The law of conservation of mass states that the total mass in a chemical reaction remains constant (that is, the reactants have the same mass as the products). The activity also gave your child a chance to think abstractly about matter. Matter is made up of smaller particles (as exhibited by the change in the shape of the container), and this matter can go through changes when energy is added.

Questions to Discuss

• Assuming that none of the steam escapes, does heating the water change the amount of water? (No. Heating water does not change the amount of water; heating the water changes the amount of energy.)
• How does changing the amount of energy influence matter? (Matter is made up of particles. When energy is added to matter, the particles that make up the matter become more active.)
• How does heating the water to boiling reveal that matter is made up of particles? (In the liquid state, the water was always the shape of the container. Once the water was heated, it started to gain energy. The more energy added, the more active the particles of water. The more active particles began to change the shape of the container.)

Things to Review

• All matter is made up of particles.
• The amount of energy in matter changes how matter acts.
• An increase in energy increases the activity of particles of matter; a decrease in energy decreases the activity of particles.