HARD
7th CBSE
IMPORTANT
Earn 100
What is a physical change, and chemical change? Give two examples of physical changes and two examples of chemical changes.
Important Questions on Physical and Chemical Changes
HARD
7th CBSE
IMPORTANT
What is meant by the rusting of iron? State two conditions necessary for the rusting of iron to occur. Explain how, rusting damages iron objects.
HARD
7th CBSE
IMPORTANT
What happens when an iron nail is kept immersed in copper sulphate solution? Write a word equation for this process. Name the type of change involved.
HARD
7th CBSE
IMPORTANT
What happens when baking soda is added to vinegar? Write a word equation for this reaction. Name the type of change which takes place.
HARD
7th CBSE
IMPORTANT
What happens when carbon dioxide gas is passed through lime water? Write a word equation for this process. Name the type of change which takes place.
HARD
7th CBSE
IMPORTANT
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is this? Explain.
HARD
7th CBSE
IMPORTANT
When a candle burns, both physical and chemical changes take place. Identify these changes.
HARD
7th CBSE
IMPORTANT
Explain why, burning of wood and cutting of wood into small pieces are considered as two different types of changes.
HARD
7th CBSE
IMPORTANT
What happens when magnesium ribbon is burnt in air? Write a word equation for this process. Name the type of change which takes place.
