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प्रश्न
Separate the following into physical and chemical changes :
Sublimation of a solid, Decomposition of water into hydrogen and oxygen by passing electric current, Formation of clouds, Making a fruit salad from raw fruits, Dissolving carbon dioxide in water
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उत्तर
Physical change: Sublimation of a solid, making a fruit salad from raw fruits, formation of clouds, and dissolution of carbon dioxide in water Chemical change: Decomposition of water into hydrogen and oxygen by passing electric current (electrolysis)
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संबंधित प्रश्न
State whether the following is physical or chemical changes.
cutting wood into small pieces —
Match the columns.
| Column A | Column B |
| 1. a change which cannot be easily reversed | a. man-made change |
| 2 a change that repeats itself at regular intervals | b. chemical chang |
| 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 formed | e. irreversible change |
| f . slow change |
Give two examples of periodic changes.
Solve this crossword by using the clues that follow-

Across
1. Energy in the form of sunlight is absorbed by the green plants in this process.
4. The reddish-brown substance formed over iron in the presence of oxygen and moisture.
5. This change is permanent and irreversible.
6. The process in which a solid directly changes into gaseous state.
Down
1 . It is the change that takes place in case of swinging pendulum of a clock. –
2. Occurrence of this is a non-periodic change as well as a natural change.
3. It is a physical change.
Fill in the blank.
The reaction in which energy is evolved is called
What will you take into account while identifying the following?
A physical change in a substance.
Differentiate between a physical change and a chemical change with reference to – Energy change taking place during the respective change.
Give a reason why – Addition of zinc nitrate to water is a physical change but, the addition of zinc to dilute nitric acid is a chemical change.
Select the chemical changes from the following list of changes
The occurrence of lightning.
Name the following.
A form of energy required for a chemical change.
