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प्रश्न
Given reason:
Burning of paper is a chemical change.
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उत्तर
When a piece of paper is burnt a new substance ash is produced. Even when the burning is stopped, the ash cannot be changed back into paper. This shows that the formation of the ash from paper is a permanent and irreversible change.
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संबंधित प्रश्न
Classify the following as chemical or physical change:
Making a fruit salad with raw fruits
Solve this crossword by using the clues that follow.
Across
1. Energy in the form of sunlight is absorbed by the green plants in this process.
4. The reddish-brown substance formed over iron in the presence of oxygen and moisture.
5. This change is permanent and irreversible.
6. The process in which a solid directly changes into gaseous state.
Down
1. It is the change that takes place in case of swinging pendulum of a clock.
2. Occurrence of this is a non-periodic change as well as a natural change.
3. It is a physical change
State whether the following is physical or chemical change.
Digestion of food —
Write true or false
Cutting of paper into pieces is a chemical change.
Name two reversible changes.
Select the chemical changes from the following list of changes
Rotting of eggs.
Higher order Thinking question
Boiling of water is a physical change; but boiling of egg is a chemical change. Why?
Analogy:
Melting of ice: Physical change.
Popping of popcorn: ______.
Water is known as a universal solvent. Why?
Mention some of the different conditions needed for chemical changes to occur.
