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प्रश्न
State whether the following is physical or chemical changes.
passing electric current through a heater rod —
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उत्तर
physical change.
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संबंधित प्रश्न
State whether the following is physical or chemical changes.
burning of wood -
State whether the following is physical or chemical changes.
Melting of wax —
True or false?
During a physical change energy is either given out or absorbed by the system.
Chemical changes are accompanied by changes in energy.
What role does energy play in initiating a chemical change ?
Under which different types can the following changes be classified?
Bursting of a cracker.
Fill in the blanks with the appropriate words of the statement given below:
Chemical changes may involve exchange of energy in the form of __________ and _________.
Some changes are listed in the following table. For each change, write in the blank column, whether the change can be reversed or not.
| S. No. | Change | Can be reversed (Yes/No) |
| 1. | The sawing of a piece of wood | |
| 2. | The melting of ice candy | |
| 3. | Dissolving sugar in water | |
| 4. | The cooking of food | |
| 5. | The ripening of a mango | |
| 6. | Souring of milk |
The difference between initial state and the final state is called change.
Cut vegetables turn brown when exposed to air, this is due to ______.
