Question

1. Which of the following is a physical change ?
a) Melting of butter
b) Burning of paper
c) Rusting of iron
d) Changing of wheat into bread
2. Milk turning sour is a chemical change ?
a) Physical change
b) Chemical change
c) Reversible change
d) None of these

Answer 1

Answers :-

1. Which of the following is a physical change ?  

a) Melting of butter

b) Burning of paper  

c) Rusting of iron  

d) Changing of wheat into bread  

• Here, melting of butter is a physical change .  

_______________

2. Milk turning sour is a chemical change ?  

a) Physical change

b) Chemical change  

c) Reversible change  

d) None of these  

• Here, milk turning sour is a physical change  

_______________

Explanation :-

PHYSICAL CHANGE :  

A physical change is a temporary change which can be reversed. These changes –  

• Are only in the state of matter  
• Are temporary  
• Can be easily reversed  
• Physical properties changes  

Example ::  

→ Changing of water to ice on cooling  

_______________

CHEMICAL CHANGE :  

A chemical change is a permanent change in the state of matter. This change cannot be reversed.  These changes –  

• Are permanent  
• Cannot be reversed  
• Result in formation of new substances  
• Chemical properties changes  

Example ::  

→ Burning of paper

_______________

Answer 2

Answer:

burning of paper is a chemical change

Milk turning sour is a chemical change

changing of wheat into bread is a chemical change

melting of butter is a physical change

I hope this helps you