W hat happens when you blow air into a balloon?
• Is there change in size?
✓ Yes ___ No
• Is there change in shape?
✓ Yes ___ No
• Is there any other change?
The balloon becomes bigger in size. It straightens up and begins to float in the air.
Activity 2: Look at the pictures and discuss about the duration for the changes to take place
Activity 3: Try to make a boat and an aeroplane one by one using the same piece of paper. This means the change of shape discussed here is reversible.
What kind of changes are they?
a) Burning of a candle.
b) Piercing a balloon with a pin.
Activity 5: Take an apple and cut it into two halves. Cut one half into pieces and share it with your friends. Is there any change in the composition of the Apple while cutting?
No, only the shape and size have changed. This can be called a physical change.
Leave the other half on the table for some time. You can see brown patches formed on the cut surface because of the reaction between some substances in the apple and the air around it. This is a Chemical change.
Activity 6: Take half a cup of water, add one spoon full of sugar and stir well.
a. What do you observe? Both of them mix and form a solution.
b. What happened to the sugar? The sugar gets dissolved in water.
c. Where is it gone? It is in the water in dissolved state.
d. The solute in the above solution is sugar.
e. The solvent in the above solution is sugar.
f. Have you seen a glass of water and a glass of sugar solution looking alike? Yes
Activity 7: Look at the pictures and write whether they are Physical or Chemical changes.
Activity 8: Look at the pictures and write whether they are desirable or undesirable changes.
Activity 9: Identify the type of changes
Natural / Human made