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प्रश्न
Write true or false
Burning of paper and formation of curd are reversible changes.
पर्याय
True
False
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उत्तर
False.
Burning of paper and formation of curd are irreversible changes.
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संबंधित प्रश्न
Classify the following as chemical or physical change:
Cutting of trees
Fill in the blank.
When a candle burns, wax melts. Melting of wax is a ________ change.
State whether the following is physical or chemical changes.
Slaking of lime —
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
Which of the following are physical changes and which are chemical changes?
Burning of candle wax, Melting of candle wax, Mixing of iron filings and sand, Burning of wood, Breaking a piece of chalk, Burning a piece of paper, Cutting a piece of paper.
State what is meant by the term – interconversion of matter. Is interconversion of matter a physical change or a chemical change.
Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
State the conclusions which can be drawn, to represent photosynthesis as a physical or a chemical change.
Select the chemical changes from the following list of changes
Respiration in mammals.
Select the chemical changes from the following list of changes
Glowing of an electric bulb.
Mention some of the different conditions needed for chemical changes to occur.
