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प्रश्न
State whether the following is physical or chemical changes.
lightning —
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उत्तर
chemical change,
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संबंधित प्रश्न
Explain the following giving an example.
Pure substance
Melting of solid (wax) is a physical change.
Write short answer.
What are man-made changes ?
State whether the following is physical or chemical changes.
cutting wood into small pieces —
Fill in the blank
Heat is ________ by a gas during the process of condensation.
Write true or false
Decomposition of leaves is a fast change.
Separate the following into physical and chemical changes :
Sublimation of a solid, Decomposition of water into hydrogen and oxygen by passing electric current, Formation of clouds, Making a fruit salad from raw fruits, Dissolving carbon dioxide in water
Fill in the blank with the appropriate word of the statement given below:
If a change is permanent and irreversible it is considered a _________ change.
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.
When ice melts to form water, change occurs in its
