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प्रश्न
Define a chemical change. Give two examples of the above changes.
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उत्तर
A permanent change in which new substances are formed whose composition and properties are completely different from those of the original
substances.
Chemical change:
(i) Burning of wood.
(ii) Breathing.
संबंधित प्रश्न
Classify the following as chemical or physical change:
Dissolving common salt in water.
Which of the following are chemical changes?
- Growth of a plant
- Rusting of iron
- Mixing of iron fillings and sand
- Cooking of food
- Digestion of food
- Freezing of water
- Burning of candle
Explain why burning of wood and cutting it into small piece are considered as two different types of changes.
State four differences between physical and chemical changes.
Name a chemical change which takes place in presence of:
State whether the following is physical or chemical changes.
growing of a piglet into a pig —
State whether the following is physical or chemical changes.
shaping a piece of glass —
True or false
In a physical change no net energy change is involved.
What are man-made changes ?
Give the main differences between physical changes and chemical changes.
Which of the following are physical changes and which are chemical changes ?
Which of the following are physical changes and which are chemical changes ?
Rusting of iron
Which of the following are physical changes and which are chemical changes ?
Glowing of an electric bulb
Given reason:
Freezing of water to ice and evaporation of water are physical changes.
Give four difference between physical and chemical changes.
State what is meant by the term – interconversion of matter. Is interconversion of matter a physical change or a chemical change.
Select the correct answer from the choice given below to complete the sentence
The energy required for completion of a physical change is ______________ when the change is reversed.
Name the following.
A form of energy required for a chemical change.
Distinguish physical and chemical changes.
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 |
