Physical changes in daily life

Change in size and shape

An activity to show change in size and shape:

• Take a sheet of paper and cut it into pieces .
• Now we cannot join the cut pieces of paper to make the original shape. 
• But each small piece of paper is still paper ; it has not changed to something else. 
• So this activity only changes the size and shape of paper. 
• No new substances are formed.
• So it is a physical change .

Change in colour

An activity to show change in colour:

• Take a hacksaw blade and hold it with tongs . Keep the other end on flame . 
• After sometime we see that tip of blade get healed and change to red in colour. 
• Now remove the blade from the burner and allow it to cool . 
• On cooling the tip, the colour returns to the original grey . 
• Temporary change in colour of take saw blade has taken place on heating
• No new substances have been formed
• Hence, it is a physical change

Change in physical state of substances 

An activity to show change in physical state:

• Take some ice in a tumbler and keep it in the sun . 
• It changes into water .
• On heating the water it changes into steam .
• if we cool the steam we get water and on freezing the water we get ice .
• We see that only the physical state has changed. 
• No new substances have been formed.
• So it is a physical change .