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प्रश्न
Assertion: Burning of wood log to charcoal is a physical change.
Reason: The products formed of burning a piece of wood can be easily converted back to wood log.
विकल्प
Both A and R are true and R is the correct explanation of A.
Both A and R are true but R is not the correct explanation of A.
A is true but R is false.
A is false but R is true.
उत्तर
Both A and R are true but R is not the correct explanation of A.
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संबंधित प्रश्न
Classify the changes involved in the following process as physical or chemical changes:
Photosynthesis
Melting of solid (wax) is a physical change.
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 three differences between evaporation and boiling
State four differences between physical and chemical changes.
Tick the most appropriate answer.
Photosynthesis requires
Two chemical substances X and Y combine together to form a product P which contains both X and Y X + Y P
X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following statements concerning X, Y and P are correct ?
- P is a compound
- X and Y are compounds
- X and Y are elements
- P has a fixed composition
Given reason:
Cutting of a cloth piece is a physical change, though it cannot be reversed.
State what is meant by the term – interconversion of matter. Is interconversion of matter a physical change or a chemical change.
Fill in the blank with the correct word of the statement given below:
Sublimation involves a __________ change.
