MEDIUM
Earn 100

Light a wax candle and observe what happens to the wax after sometime. Now putoff the candle and observe what happens to the melted wax.

Important Questions on Changes Around Us

MEDIUM
Science>Chemistry>Changes Around Us>Classification of Changes
How would you show that setting of curd is a chemical change?
HARD
Science>Chemistry>Changes Around Us>Classification of Changes
Dissolution of a sugar cube in water is a physical change while burning a sugar cube is a chemical change. Why?
MEDIUM
Science>Chemistry>Changes Around Us>Classification of Changes
What are the differences between a physical and a chemical change? 
MEDIUM
Science>Chemistry>Changes Around Us>Classification of Changes
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it?
HARD
Science>Chemistry>Changes Around Us>Classification of Changes
Cutting a potato is a physical change while cooking it is a chemical change. Explain how.
MEDIUM
Science>Chemistry>Changes Around Us>Classification of Changes
What kind of change occurs when a pot is made from clay?
MEDIUM
Science>Chemistry>Changes Around Us>Classification of Changes
Explain why burning of wood and cutting it into small pieces is considered as two different types of changes.
EASY
Science>Chemistry>Changes Around Us>Classification of Changes
What happens to the wax when we burn a candle? 
EASY
Science>Chemistry>Changes Around Us>Classification of Changes

State two ways by which a change can be brought about.

EASY
Science>Chemistry>Changes Around Us>Classification of Changes
What does the physical change mean?
MEDIUM
Science>Chemistry>Changes Around Us>Classification of Changes
Anaerobic bacteria digest animal waste and produce biogas (Change — A). The biogas is then burnt as fuel (Change — B). The following statements pertain to these changes. Choose the correct one.
(i) Process — A is a chemical change.
(ii) Process — B is a chemical change.
(iii) Both processes A and B are chemical changes.
(iv) None of these processes is a chemical change.
EASY
Science>Chemistry>Changes Around Us>Classification of Changes
Select the material that undergoes the change.
  • A sheet of paper cut with a pair of scissors.
MEDIUM
Science>Chemistry>Changes Around Us>Classification of Changes
Melting and freezing of wax are _____ changes. (physical / chemical)
HARD
Science>Chemistry>Changes Around Us>Classification of Changes
Classify the changes involved in the following processes as physical or chemical changes:
(A) Photosynthesis
(B) Dissolving sugar in water
(C) Burning of coal
(D) Melting of wax
(E) Beating aluminium to make aluminium foil
(F) Digestion of food
MEDIUM
Science>Chemistry>Changes Around Us>Classification of Changes
Why is germination of a seed a chemical change?
MEDIUM
Science>Chemistry>Changes Around Us>Classification of Changes
What kinds of changes occur when a candle burns?
EASY
Science>Chemistry>Changes Around Us>Classification of Changes
Cotyledons are also called-
EASY
Science>Chemistry>Changes Around Us>Classification of Changes
What are physical and chemical changes? Give an example of each.
EASY
Science>Chemistry>Changes Around Us>Classification of Changes
What does chemical change mean?
HARD
Science>Chemistry>Changes Around Us>Classification of Changes
The gas we use in the kitchen is called liquefied petroleum gas (LPG). In the cylinder it exists as a liquid. When it comes out from the cylinder it becomes a gas (Change — A) then it burns (Change — B). The following statements pertain to these changes. Choose the correct one.
(i) Process — A is a chemical change.
(ii) Process — B is a chemical change.
(iii) Both processes A and B are chemical changes.
(iv) None of these processes is a chemical change.