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प्रश्न
Write true or false
Burning of sugar is a temporary change.
विकल्प
True
False
उत्तर
False
APPEARS IN
संबंधित प्रश्न
Tick the most appropriate answer
2. Melting of ice is a
- reversible change
- irreversible change
- chemical change
- none of these
Write true or false for the statement
Decomposition of leaves is a fast change.
How do you say that the process of digestion is a chemical change ?
What role does energy play in initiating a chemical change ?
Classify the following changes as physical or chemical:- photosynthesis in plants
Tick (√) the correct alternative from the choice given for the following statement
Which one of the following is volatile in nature ?
Give reasons why – separation of mixtures e.g. iron from a mixture of iron and sulphur is a physical change, but heating a mixture of iron and sulphur is considered a chemical change.
Fill in the blank with the appropriate word of the statement given below:
Germination of seeds is considered a __________ change.
Match the examples of changes in List I with the correct.
| List I | List II |
| 1. Expansion of a steel rod on heating | A: Physical change |
| 2. Rotting of eggs | B: Chemical change |
| 3. Milk turning sour | |
| 4. Tarnishing of copper | |
| 5. Separation of naphthalene from a mixture of naphthalene and sodium chloride. |
Potassium chloride is added to water and stirred. A salt solution is obtained, which is then boiled, leaving behind a residue.
- Is the above change physical or chemical?
- Name the residue which remains behind after the salt solution is boiled.
- Is the change reversible or not reversible?
- Are the composition and properties of the original substance altered?
- Give a reason why the above experimentation would not be possible if calcium carbonate was taken in place of potassium chloride.
