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Expansion and Contraction - Closed-ended activity


Plan Author: David Riddick
Date Created: 10/28/2002 8:48:39 PM PST


Dyer St. Elementary

Grade Level:

31 Students. 20 boys and 11 girls. 10 E0s; 10 RFP's 10 ELD4-5: 1 ELD2. GATE class - advanced learners

Subject Area(s):

Students will have an appreciation of how temperature affects gas molecules.

Students learn temperature affects gas molecules, gas molecules expand when heated and contract when cooled.


CA- CCTC: Aligned CSTP's and TPE's

• Standard : CSTP: Standard for Understanding and Organizing Subject Matter for Student Learning
TPE: A. Making Subject Matter Comprehensible to Students
CSTP Description: Teachers exhibit strong working knowledge of subject matter and student development. Teachers organize curriculum to facilitate students’ understanding of the central themes, concepts, and skills in the subject area. Teachers interrelate ideas and information within and across curricular areas to extend students’ understanding. Teachers use their knowledge of student development, subject matter, instructional resources and teaching strategies to make subject matter accessible to all students.

• CSTP Key Element : Developing student understanding through instructional strategies that are appropriate to the subject matter.

 Question : help all students develop enthusiasm for and a deep knowledge of the subject matter?

CA- California K-12 Academic Content Standards

• Subject : Science

• Grade : Grade Five

• Area : Physical Sciences

• Sub-Strand 1: Elements and their combinations account for all the varied types of matter in the world. As a basis for understanding this concept:

 Standard b: Students know all matter is made of atoms, which may combine to form molecules.

 Standard g: Students know properties of solid, liquid, and gaseous substances, such as sugar (C 6 H 12 O 6 ), water (H 2 O), helium (He), oxygen (O 2 ), nitrogen (N 2 ), and carbon dioxide (CO 2 ).

Cognitive: Students will learn molecules expand when heated and contract when cooled.

Observable behavior: Students will work in cooperative groups on their experiments and record steps of the scientific method.

Criteria: Given questions on expansion & contraction, students will demonstrate understanding of the concepts of expansion & contraction of gas molecules with 80% accuracy.

Prerequisite Background Skills/Knowledge:
Students should be cognizant that all matter is made of atoms, which are formed from protons, neutrons, and electrons. Atoms combine to form the molecules that make up matter. Molecules have an attractive force (cohesion) between them.

Vocabulary / Language Skills:
Listening: Students listen to verbal instructions given during directed lesson. ELD students are given help by peer tutors as teacher speaks.

Speaking: Students participate in directed lesson by raising hands and answering questions.

Writing: Students will take notes from the directed lesson and place in science notebook.

Reading: Students read from "molecular" handout.

Vocabulary: Molecules, atoms, protons, neutrons, electrons, gases, ions, physical properties

1) Pencil & Paper
2) Science notebooks
3) Transparencies
4) Transparency pen
5) 8 Empty 2 liter bottle (cooled)
6) 8 Round balloons
7) Bucket of hot water 1/2 filled
8) Computers - Internet - "Google"
9) "Molecular" Handout
10) Ice chest to store cold liter bottles

Classroom Management:
During directed lesson, students are seated in assigned seats, which are 2-person desks.

I will give out extra credit points for students who participate and cooperate with lesson.

Extra credit points for actively engaged students

Procedure: Open

As an attention getter, I call on students who have transitioned well into Science to be the first volunteers to share what they know about Molecules.

I will give out extra credit points for students who participate and who are actively engaged.

Procedure: Body


1st: Point our standards we are working on (posted).

2nd: Establish a sense of academia by introducing vocabulary for this lesson. Review the background vocabulary they need to know, and deepen their understanding by illustrating a water molecule on the board.

3rd: I will describe how molecules have an attractive force (cohesion) between them. There is a space between molecules. Gas molecules are wider than liquid and solid molecules. Gas molecules have almost no cohesive attraction.

4th: I will ask students what they think will happen to air in a bottle if it is heated.

5th: I will explain gas molecules can conform to a container shape or escape from an uncovered container.

6th: We will read the handout on gas "Molecular" activity.

7th: Students will get into cooperative groups quietly.

8th: I will model the experiment as students follow the steps.
a) Snap the balloon over the bottle.
b) Wrap both hands around the bottle to warm it. Let a partner help, too.
c) Students will write in their notebooks what happens to the balloon.
d) After students heat the bottle, they will allow it to cool. Students will log what happens as the bottle cools.

9th: I will promote high level thinking and/or open-ended questions by asking them to place their bottle in the sun and predict what will happen to the balloon. The students will be encouraged to place the bottle in different locations to find what will happen to the attached balloons.

Guided Practice:

I will describe how molecules expand when heated and contrast when cooled.

I will demonstrate how to place the balloon over the bottles.

To check for understanding, I use non-verbal hand cues to assess for confusion and clarification.

Independent Practice:

Students will place the balloons over the bottles and heat them.

Students will log what happens to the gas molecules when they are heated and cooled.

Students will work in cooperative groups to discover their answers together.

High achieving students will expand their research by looking up information on molecular activity on the computer.

Procedure: Close

To close the lesson and summarize what was learned, students will reflect in their journals what they learned and vocabulary introduced. I will hand it over to the class to discuss what they learned, giving them ownership of their learning.

Students will demonstrate their learning of molecular expansion and contraction by answering the following questions with 80% accuracy.
1) What happens to the balloon?
2) What seems to be happening to the air inside the bottle?
3) What happens to the balloon when the bottle cools? Why?
4) What happens to molecules when they are heated? When cooled?


The objective of the lesson was achieved. I know the objective was achieved because the students were able to articulate orally and written why the air in the bottle expanded and contracted. I correctly anticipated and prevented the lesson from getting chaotic. The students were focused and on task during the experiment.

One of the most effective things I did was keeping the students on the edge of their seats. I didn't have a lot of down time for them to get into mischief. I kept the lesson going at a good pace.

However, I did not anticipate the clean up properly. I haphazardly selected students to clean up the class without much guidance or instruction. The class became a little disruptive and unfocused during clean up.

Overall, the lesson went extremely well. The students were on task. I rehearsed the experiment at home first. I anticipated potential problems and enabled the procedures to run smoothly.

If I were to teach this lesson again, I would assign students ahead of time for clean up, rather than the free for all clean up that resulted.

The lesson was relevant and worthwhile for the students. I believe the hands on element of the lesson provided greater insight to expansion and contraction of molecules.

In meeting the standard for Understanding and Organizing Subject Matter for Student Learning, I tried to make the lesson tangible and accessible. I wanted develop an enthusiasm and a deep knowledge for molecular activity by creating a hands on experiment.