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प्रश्न
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
Do you think rust is different from iron?
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उत्तर
Yes, rust is different from iron. It is a brown powder of iron oxide.
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संबंधित प्रश्न
Choose the most appropriate answer.
Rising and setting of the sun at a given place is a
Is burning a physical change or a chemical change? Why?
Separate the following into physical and chemical changes :
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- decaying of wood
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- sawing of wood
- hammering of nail into wood
Classify the Following as a Physical Or a Chemical Change.
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Fill in the blank.
The process of a liquid changing into a solid is called ________
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.
Select the correct answer from the choice given below to complete the sentence
The dissolution of lead nitrate in water is deemed as a _________ change.
Stretching gold coin into a ring is a ______ change.
Cutting a log of wood into pieces is a chemical change.
