Advertisements
Advertisements
प्रश्न
Paheli had bought a new bottle of pickle from the market. She tried to open the metal cap to taste it but could not do so. She then took a bowl of hot water and immersed the upper end of the bottle in it for five minutes. She could easily open the bottle now. Can you give the reason for this?
Advertisements
उत्तर
On immersing in hot water, the metal cap expands in size hence it can be removed easily.
APPEARS IN
संबंधित प्रश्न
Very Short Answer Type Question:
Give two examples of irreversible changes.
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 happens when sugar is heated?
Circle the odd one.
Most of the physical changes are ______.
Differences between
reversible and irreversible changes are:
Analogy:
Irreversible change: Making idly front batter.
Reversible change: ______.
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
Can we reverse the following change? If yes, suggest the name of the method.
Water into water vapour
Choose the odd one out. Give reason for your choice.
