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प्रश्न
Give three reasons why melting of wax, is considered a physical change while burning of a candle, a chemical change.
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उत्तर
Melting of wax is a temporary and reversible change on cooling, wax solidifies, and no new product is formed while burning of a candle is a permanent change i.e. products are not convertible, a new substance is formed having different composition & different properties.
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संबंधित प्रश्न
Classify the following as chemical or physical change:
Melting of butter in a pan
Classify the following as chemical or physical change:
Passing of electric current through water, and water breaking down into hydrogen and oxygen gases.
Define physical change. Give two examples for the above changes.
State whether the following is physical or chemical changes.
growing of a piglet into a pig —
The rusting of an iron object is called :
Ice kept in a beaker, slowly melts and turns into water. The water in the beaker on solidification is freezing turns back to ice. Give four reasons why the change from ice to water and water back to ice is considered a physical change.
Name the following:
The term involved in the change of state from – ‘water to ice’ – which is a physical change.
Change is the law of nature which occurs in everyday life.
State when a substance [i.e. matter] undergoes a kind of change.
Give a reason why
Change of seasons is a periodic change while the change of weather is a non-periodic change.
Give the reason why the following is considered as chemical changes.
Copper carbonate on heat gives copper oxide and carbon dioxide.
