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प्रश्न
Fill in the blank.
The reaction in which energy is evolved is called
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उत्तर
The reaction in which energy is evolved is called exothermic reaction.
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संबंधित प्रश्न
Tick the most appropriate answer.
4. Chemical changes involve
- change in shape.
- change in size.
- change in molecular composition.
- none of these
Write true or false for the statement.
Deforestation is a man-made change
Write true or false for the statement.
Dissolving of solute in a solvent and rusting of iron are both physical changes.
State whether the following is physical or chemical changes.
cutting wood into small pieces —
Tick (√) the correct alternative from the choice given for the following statement
A pop sound is heard when a lighted match stick is brought near the mouth of a jar. This indicates the release of gas.
Write true or false
A natural change can also be a desirable change.
Give the reason why the following is considered as chemical changes.
Copper carbonate on heat gives copper oxide and carbon dioxide.
Match the items of Column I with the items of Column II.
| Column I | Column II | ||
| (a) | Large crystals | (i) | Turns lime water into milky |
| (b) | Depositing a layer of zinc on iron | (ii) | Physical change |
| (c) | Souring of milk | (iii) | Rust |
| (d) | Carbon dioxide | (iv) | Sugar candy (Mishri) |
| (e) | Iron oxide | (v) | Chemical change |
| (f) | Dissolving common salt in water | (vi) | Galvanisation |
Keeping a stone in sunlight for few hours is ______.
Which of the following is not a physical change?
