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प्रश्न
Define physical change. Give two examples for the above changes.
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उत्तर
Physical change: A temporary change in which no new substance is formed, the composition of substance remains the same, though its state, shape and size may change.
Example of physical change:
- Change of water into its vapours.
- Heating of iron rod.
संबंधित प्रश्न
Classify the following as chemical or physical change:
Melting of butter in a pan
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Cutting a log of wood into pieces is a chemical change.
Match the columns
| column A | coulmn B |
| 1. A change which cannot be easily reversed | a. man-made change |
| 2.A change that repeats itself at regular intervals | b. chemical change |
| 3. A change that is made by humans | c. physical change |
|
4. A change in which the original substance cannot be obtained |
d. periodic change |
| 5. A change where no new substance is formade | e. irreversible change |
| f. slow change |
Dissolving salt in water is a reversible change.
A burning candle shows both physical and chemical changes. Explain ?
State whether the following is physical or chemical changes.
cutting wood into small pieces —
Classify the following changes as physical or chemical.
State the various conditions that favour the process of evaporation.
Classify the following as a physical or a chemical change.
Drying of wet clothes
Given reason:
Burning of paper is a chemical change.
Distinguish between the following.
Physical change and chemical change
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.
State which of the following terms connected with change of state of matter i.e.
(a) Melting
(b) Vaporisation
(c) Condensation
(d) Freezing
pertain to –
- Conversion of a liquid into a vapour or gas.
- Conversion of a liquid into a solid.
- Conversion of a solid into a liquid on heating.
Select the chemical changes from the following list of changes
Glowing of an electric bulb.
Select the correct answer from the choice given below to complete the sentence
A change in which a substance retains its identity is a
______ change.
Name the following.
A form of energy required for a chemical change.
Distinguish physical and chemical changes.
What kind of change is shown by tearing of paper?
Give two examples for the following case:
Physical changes which are not reversible
