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प्रश्न
Boojho’s sister broke a white dove, a symbol of peace, made of Plaster of Paris (POP). Boojho tried to reconstruct the toy by making a powder of the broken pieces and then making a paste by mixing water. Will he be successful in his effort? Justify your answer.
उत्तर
Boojho will not be successful because making of toy from Plaster of Paris (POP) is an irreversible change. Once the Plaster of Paris is mixed with water and dried it cannot regain its properties.
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संबंधित प्रश्न
Very Short Answer Type Question:
Some common changes are given in the below Table. Which of these changes do you think can be reversed?
| Change | Can be reversed |
| (i) Raw egg to boiled egg | Yes/No |
| (ii) Batter to idli | |
| (iii) Wet clothes to dirty clothes | |
| (iv) Woollen yarn to knitted sweater | |
| (v) Grain to its flour | |
| (vi) Cold milk to hot milk | |
| (vii) straight string to a cold string | |
| (viii) Bud to flower | |
| (ix) Milk to paneer | |
| (x) Cow dung to biogas | |
| (xi) stretched rubber band to its normal size | |
| (xii) Melting of ice-cream |
Short Answer Type Question:
What is a chemical change? Explain with example.
Circle the odd one.
Choose the odd one out. Give reason for your choice.
When ‘Touch me not’ plant is touched by us, ______ changes occur.
While lighting a candle, Paheli observed the following changes.
- Wax was melting
- Candle was burning
- Size of the candle was reducing
- Melted wax was getting solidified. of the above, the changes that can be reversed are
Give one example of change which occurs on heating but can be reversed.
Circle the odd one out. Give reason for your choice.
Choose the odd one out. Give reason for your choice.
Find the odd one out. Give reason for your choice.
