What A Gas!

Trudy S. Moore                 Scott Joplin Elementary School
                               7931 S. Honore Ave.
                               Chicago IL 60620  
                               (773) 535-3425 

Objectives: 
    
    This lesson is designed for students in grades K-4.  Students will be able 
to understand and explain that: 
     1. air occupies space
     2. the visual effects of air and
     3. how air exerts force

Materials:
    
     Activity 1--Blowing Bubbles
          Bubble liquid solution, Styrofoam cups, drinking straws, tin pan(s), 
          paper towel and pencils.
     Activity 2--Nature Walk
          Pens/pencils, paper and mirrors
     Activity 3--Streamers in the Wind
          Colorful crepe paper for streamers, empty paper towel rolls for each 
          child, stapler and staples, construction paper and glue, paints and 
          brushes or crayons and string or yarn. 
     Activity 4--Balancing Balls
          Bendy drinking straws and Styrofoam balls (small to medium)
     Activity 5--Blow Your Horn
          A balloon and noisemakers for every student
     Activity 6--Can Crusher
          Several empty soda pop cans, hot plate or burner, tongs, water and 
          large container of ice water 
     Activity 7--Egg-in-a-bottle Brain Teaser
          Hard boiled egg with shell removed, flask or bottle with mouth smaller 
          than egg, lighter/matches and scrap paper.

Strategies:

         1. Blowing Bubbles
         Buy bubble liquid from discount store or make your own by mixing two 
cups of water to two tablespoons of liquid soap for each group of children.  
Give each group a tin pan with bubble mixture.  Do this activity indoors or out, 
but have plenty paper towels on hand for spills.  Begin by asking children 
what's a bubble made of?  What makes it float?  Give each one a Styrofoam cup 
and a drinking straw.  Demonstrate how to use a pencil to make a hole just large 
enough for the straw to be inserted into one side near the bottom.  Have one 
child at a time place his or her cup mouth down into the soapy mixture until a 
film forms across the top.  Slowly lift the cup from the pan and turn it right 
side up.  Blow gently into straw to form bubbles.  Discuss: bubble-blowing 
techniques, correlation between the amount of air and size of bubble and what 
happens when a bubble bursts. 


         2. Nature Walk
         Discuss how we can feel air in different situations (waving hands, 
turning on a fan etc.).  How do we know it's there if we really can't see it? 
Pull out a mirror and breathe on it to show children how water droplets from 
breath have collected on the glass to "show" the air.  Explain that while we 
can't see air, we can view its effect on other objects.  Take children outside 
on a day when weather permits.  Ask them to observe what evidence they see of 
the wind/air around them even though they can't see it.  Have them jot down 
things that are being moved by the wind (leaves on trees, hair, skirts or 
dresses, grass, paper on the ground, dirt etc.).  When you return to the 
classroom, discuss their observations and write a one-page essay or poem on the 
effects of wind. 

          3. Streamers in the Wind
          Children can cover an empty paper towel roll with construction paper 
or color or paint the cardboard tubing.  Then cut three-feet long strips of 
crepe paper and give each child three strips.  Staple streamers at both ends and 
in the middle of the cardboard tube.  Thread about a foot of yarn or string 
through tubing and secure with a knot.  Take children outside and have them hold 
the banner by the yarn/string and run, twirl and wave the banner.  How does the 
wind effect the streamers? 

          4. Balancing Ball Act
          Give each child a bendy drinking straw.  Styrofoam balls can be given 
out in small groups of 2 or 3 or individually.  Have children bend straw so that 
collapsible end points upward at a 90 degree angle.  With straws in their 
mouths, children gently place the styrofoam ball at the end of the straw and 
remove their hand as they begin to gently blow.  Observe how the air travels 
through the bent straw and, depending on the force of the air and size of ball, 
can hold the ball in mid-air.  Discuss the suspension of the ball in the air. 
How is it being held in place?  Are there any other ways to achieve suspension 
of the ball?  Let kids experiment on their own or in groups.  How does varying 
the force of air on the ball effect it?  Have them barely blow through the straw 
and then blow as hard as they can and compare results. 

          5. Blow Your Horn 
          Have a toy horn or party noisemakers for every student.  After they've 
had an opportunity to blow the horns and/or noisemakers, discuss what makes the 
sound (the air traveling through the horn or noisemaker).  Then ask them if they 
can think of any way to blow the horn without putting their mouths on the 
noisemakers.  Accept appropriate responses.  Then hand out a balloon to each 
child.  Give them another opportunity to answer the previous question.  Now have 
them inflate their balloons.  Holding the balloons so the air does not escape, 
insert the mouthpiece of a horn or noisemaker into balloon.  What happens?  (If 
necessary, squeeze balloon to force air through noisemaker). 

         6. Can Crusher
         Put a few drops of water into an empty soda can.  Place can on burner 
until steam starts to escape.  Remove hot can from heat source with tongs. 
Quickly invert can into container of ice water.  The can collapses. Have 
children theorize why can collapses.  Accept appropriate responses indicating 
critical thinking.  Explain that when the can was heated and the steam started 
to rise, the air molecules were moving very quickly.  When the hot can is 
plunged into cold water, the air molecules are cooled quickly and start to draw 
together, thereby crushing the can. 

         7. Egg-in-a-bottle Brain Teaser
         Strike a match and light a small piece of paper.  Place burning paper 
in a jar and put the small end of egg on top of the mouth of the bottle.  The 
fire heats up the air inside the bottle and the egg starts to "dance".  Since 
the fire consumes the oxygen in the bottle, the air pressure outside the bottle 
is greater than the air pressure inside the bottle.  The outside air pressure 
pushes the egg into the bottle.  Ask children if they can think of a way to get 
the egg out of the bottle without breaking the bottle.  You can heat the bottle 
and then turn it upside down or hold it upside down and blow into it.  This 
increases the air pressure inside the bottle and forces the egg out.  
Demonstrate both. 
    
Performance Assessment:

     To assess children's knowledge of the subject matter, have each child 
select one activity done in class to demonstrate and explain before the 
class.  In addition to doing the experiment, the student should be able to 
answer questions regarding the effects of air as well as how air occupies space 
and exerts force. 

References:

     Esler, Mary K. and William K. Teaching Elementary Science (7th ed.).  
Belmont, CA: Wadsworth Publishing Co., 1996.

     UNESCO (United Nations Educational, Scientific, and Cultural Organization). 
700 Science Experiments For Everyone. New York: Doubleday, 1962.