Question

E. Answer the following questions. 1. How are reversible changes different from irreversible changes? Give two examples for each type. 2. Classify the following as reversible or irreversible changes: (a) melting of butter, (b) ripening of mango, (c) expansion of a metal, and (d) baking of a cake. 3. Name the three physical states of water. Explain the statement: The change of states of water is a reversible change. 4. What are physical changes? Give two examples. 5. What are chemical changes? Give two examples. 6. Why does an inflated balloon shrink in size when kept inside a freezer?​

Answer 1

Answer:

1)

reversible changes are those changes which can be reversed from their original state

and irreversible are those which we cannot obtain again

reversible changes ex:-water to ice

stretching of rubber

irreversible changes ex:- wheat flour to chappati

carrot to carrot juice

2)

a reversible

b irreversible

c irreversible

d irreversible

3)

three physical states of water are solid , liquid , gas

yes change of state of water is reversible because by changing temperature we can obtain these states again and again

like if we increase temp of ice continously then solid will convert into liquid amd liquid will convert into gaseous form called as vapours

and if we decrease the temperature of vapours continously they will convert into liquid and further solid

4)

Physical change is a type of change where the physical properties of matter change. A change of state of matter, change in colour, odour, solubility, etc. all are examples of physical change.

5)

A chemical change is a type of change where the chemical properties of matter change. It is commonly called a chemical reaction.

Examples of Chemical Change

Combustion, rusting, fermentation, etc. are a few examples of chemical change.

6)The frozen balloon shrank because the average kinetic energy of the gas molecules in a balloon decreases when the temperature decreases. This makes the molecules move more slowly and have less frequent and weaker collisions with the inside wall of the balloon, which causes the balloon to shrink a little.