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प्रश्न
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.
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उत्तर
Physical change: Melting of candle wax, mixing of iron filings and sand, Breaking a piece of chalk, and Cutting a piece of paper.
Chemical change: Burning of candle wax, burning of wood, and Burning a piece of paper.
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संबंधित प्रश्न
Classify the following as chemical or physical change:
Rusting of almirah
Try segregating the things around you as pure substances or mixtures.
Melting of solid (wax) is a physical change.
State whether the following is physical or chemical changes.
heating a mixture of iron filings and sulphur—
Read the paragraph and note down the various types of changes it mentions.
It was nearing six o'clock in the evening. The sun was setting. A breeze was blowing. Leaves on the tree were shaking. Sahil was sitting in the courtyard, rolling balls of wet soil, and shaping them into various toys. Then he felt hungry and went into the house. Mother made a dough from wheat flour and fried purees. While eating hot purees, his attention was drawn outside the window. It had started raining. There was lightning, too. Sahil was enjoying his dinner in the dim light.
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.
Match the examples of changes in List I with the correct.
| List I | List II |
| 1. Expansion of a steel rod on heating | A: Physical change |
| 2. Rotting of eggs | B: Chemical change |
| 3. Milk turning sour | |
| 4. Tarnishing of copper | |
| 5. Separation of naphthalene from a mixture of naphthalene and sodium chloride. |
Stretching gold coin into a ring is a ______ change.
Assertion: The explosion of fire cracker is a physical change.
Reason: A physical change is a reversible change.
When solute is dissolved in a solvent it forms a solution.
