Summer Research Program for Science Teachers

Jennifer A. Clark

Talent Unlimited HS

August 2005

Unit 2: The Physical Behavior of Matter

Topics: Molecular organization of solids, liquids and gases

SWR: Macro-level distinctions between three phases of matter: solid, liquid, and gas.

SWBAT: Distinguish between three phases of matter: solid, liquid and gas, on the molecular level. Compare and predict the relative compressibility of the three phases of matter.

Aim: What are three phases of matter and how do we compare their similarities and differences?

Do Now: Complete #1- 4 below in your notebook. Write down answers to questions only.

1. List the three phases of matter that you know of.

2. Describe 1-2 similarities that all of these phases share.

3. Describe 2-3 differences between these phases (in terms of what you have observed of substances in each of these phases).

4. In your notebook, draw three images. Each image should represent one of the three phases. For example, one image should represent a solid phase, one image should represent a liquid phase and one should represent a gas phase.

Vocabulary: Matter, substance, phase, solid, liquid, gas, molecule, atom, macro-level, molecular level, compressibility and hypothesis.

Materials: 1. Balloons. 2. Water.

1. Students are instructed to copy down the aim question and complete the do now assignment in their notebooks individually.

2. 2-3 students are called upon to draw their images from #4 in the do now on the board.

3. As a class, we review students’ answers to the do now assignment.

4. Students are asked to consider the images which are drawn on the board, as well as the images which are drawn on their own papers. Students are asked to compare observable differences between the three phases of matter.

5. The teacher constructs a list/ven diagram/graphic organizer to display the similarities and differences between the three phases of matter on the macro level.

6. Students are asked to account for the observable differences on the macro level by considering differences between the phases on the molecular level.

7. Students are instructed to draw each of the three phases on the molecular level. Then, they must describe how the three phases are similar and how they are different.

8. Students are engaged in a discussion about their drawings, and are guided towards an understanding of the differences between three phases of matter on the molecular level.

9. Students are asked to apply their new understanding of the differences between the three phases of matter to the concept of compressibility. Students are asked to predict the compressibility between solids, liquids and gases.

10. Demonstration: A student is asked to fill a balloon with water. Once the balloon is filled and tied, the student is asked to throw the balloon at the chalkboard (or some area of the room which will be unharmed by water from the balloon). When the water balloon breaks, students may be asked to describe what happened and why. Next, a pre-prepared balloon (one which was filled with water and then filled with some air) is handed to another student volunteer under the pretense that it is a water balloon just like the one that they just observed. The student is asked to throw the balloon in the same direction as the last balloon. (The balloon should not break, or not as easily as the balloon which only contained water with no added air). Students are asked why the second balloon would not break.

11. Students are engaged in a discussion regarding the compressibility of the three phases of matter in relation to the molecular packing of each phase. Students are guided toward an understanding that gas is more compressible due to the relatively greater space between its particles, allowing it to act as a cushion, absorbing impact, in the second balloon which prevented the balloon from breaking.

1. What are some observable similarities and differences between the three phases of matter?

2. What are the similarities and differences between the three phases of matter on the molecular level?

3. Why does the first balloon break more easily than the second balloon? Why do air bags contain air, and not something in the liquid or solid phase?

4. How does the compressibility of air allow it to absorb energy from an impact more effectively than a liquid or a solid?

Summary: Students must answer the following questions in their notebooks:

1. What are the three phases of matter and how do we compare their similarities and differences?

2. Which of the three phases of matter contains molecules which are most tightly packed? Least tightly packed?

3. Which of the three phases of matter is most compressible? Why?

Homework: Answer the following questions on a separate sheet of paper:

Q1. Can a substance have one, two or all three phases of matter? Explain your answer using three different substances as examples.

Q2. Using one of the substances that you listed above, briefly describe how you might prove whether or not this substance could exist in one, two or all three phases. For example, design an experiment to prove or disprove your hypothesis.