Objective: Children know what is air and have experienced its presence through wind. But they don’t know that like any other object air too has weight, it occupies space and it is able to exert pressure on other objects.
Materials:
Glass bowl
Large container
Balloons
Safety pin
Paper piece
Thread
Inflated ball
Lesson One
- Begin your class by instructing students to talk what they know about air.
- Instruct your students to fill the large container with water. Don’t fill it completely because if you do so, you may spill excess water while you push the glass bowl.
- Stick the paper piece tightly in the bottom of the glass bowl so that it won’t fall down while you immerse the glass bowl.
- Immerse the glass bowl in water by holding it upside down. Don’t take your hand from the glass bowl. Ask them whether the paper piece will be dry or wet. Now slowly take the glass out of the water without tilting it and remove the paper piece. Instruct the students to record their observation.
Lesson Two
- Divide students into small groups and provide each group with two balloons, small thread and paper pieces. Instruct them to inflate it. Now tightly tie the thread around the mouth of the balloons and keep it aside.
- Puncture one inflated balloon with the pin and hold the paper piece in front of the small hole.
Analysis and conclusion: Children will experience the presence of air which flows out of the inflated balloon from the flickering of the paper piece. Analyzing the result of these experiments they will arrive at the conclusion that air takes space.
Lesson Three
- Take the second balloon and puncture it. But this time instead of holding the paper in front of it, instruct them to try to seal the small hole using this paper. It is not possible as the air pushes the paper piece backward.
- Take the inflated ball and push the inflated ball forcefully to the ground, it will bounce back. Decrease the amount of air inside the ball and repeat the same experiment until there is no air. Instruct the students to record the observation. In this activity it exerted pressure in the ground to bounce back. Each time, the height attained becomes less as the amount of air inside the ball decreases.
Analysis and conclusion: From the observation they will arrive at the conclusion that air can exert pressure.
Lesson Four
Materials:
Two Balloons
Long thin stick
Thread
Procedure:
- Inflate the two balloons and seal them. Tie each of them at each end of the stick and balance it by placing it horizontally across the table. Care should be taken that each of the balloon is of the same size and is equally inflated and the stick is long enough so that both balloons hang freely from the sides of the table.
- Puncture one of the balloon with the pin and observe the result. Slowly the other balloon will fall into the floor.
Analysis and conclusion:
From the observation students will understand that there is balance when both have the same weight. As soon as one of the balloon was punctured its weight started to decrease and the balance was lost. Students will arrive at the conclusion that air too has weight.
