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प्रश्न
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.
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उत्तर
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संबंधित प्रश्न
Classify the changes involved in the following process as physical or chemical changes:
Photosynthesis
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 |
Is burning a physical change or a chemical change? Why?
Write true or false
Melting of ice is a physical change.
What is a chemical change ? Give two examples of chemical changes.
Change is the law of nature and occurs in our everyday life, at all times and in all places.
Differentiate between the following change with a suitable example.
Slow and fast change.
Differentiate between a physical change and a chemical change with reference to – Formation of products.
Give the reason why the following is considered as chemical changes.
Sulphur when burnt in air evolves a gaseous acidic product.
Natural changes which take place in nature on their own, are beyond the control of human being.
Give an example to justify the statement that physical changes can be reversible as well as irreversible.
