When Is A Balloon The Biggest

Standard and objective: 3a, b Investigate the motion of particles. a. Identify evidence that particles are in constant motion. b. Compare the motion of particles at various temperatures by measuring changes in the volume of gases, liquids, or solids. Activity title: Where is the balloon the biggest? Description: The students will measure the diameter of a balloon full of air. Put the balloon into a microwave and heat for 5-10 seconds and re-measure. Put the balloon into a freezer for 5-10 minutes and re-measure. Materials needed: Balloons, string, metric ruler, Microwave and freezer. The same results can be obtained using a hair dryer and a sink of cold water. Prior knowledge needed: Particles move. Time required: 15 minutes to 1 period Special teacher procedures, safety notes, and suggestions: This can be done as homework, demo, or activity. Have the students draw a line with a marker on the balloon where it will be measured. Depending upon the type of balloon the time in the freezer and the microwave will vary. Test it first with the ones that you have. 1. Blow up the balloon and draw a line around the middle. Using a string measure the Circumference. Record 2. Put the balloon into the freezer for 5-10 minutes. Quickly take it out and remeasure along the same line. 3. Put the balloon in the microwave and heat for 1-4 minutes. Quickly take it out and re-measure along the same line. 4. Answer these questions. a. Why did the balloon seem to shrink? b. Why did the balloon seem to get bigger? c. Draw sketches that would show both processes. Student sheet or handout (if needed): none Scoring guide: None

Name _______________ Period ___ Where is the balloon the biggest? 1. Blow up the balloon and draw a line around the middle. Using a string measure the Circumference. Record

2. Put the balloon into the freezer for 5-10 minutes. Quickly take it out and remeasure along the same line. 3. Put the balloon in the microwave and heat for 1-4 minutes. Quickly take it out and re-measure along the same line. Data Circumference Beginning Circumference Freezer circumference Microwave circumference Answer these questions. 1. Why did the balloon seem to shrink?

2. Why did the balloon seem to get bigger?

Draw sketches that would show both processes

Bigger/Smaller/no change