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प्रश्न
What is a chemical change ? Give two examples of chemical changes.
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उत्तर
Chemical change: These changes occur when a substance combines with another to form a new substance. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions.
Examples:
- Rusting of iron
- Burning of paper
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संबंधित प्रश्न
State whether the following is physical or chemical changes.
water cycle in nature —
Tick (√) the correct alternative from the choice given for the following statement
A pop sound is heard when a lighted match stick is brought near the mouth of a jar. This indicates the release of gas.
Photosynthesis cannot take place at night.
State one instance where water undergoes a physical change and one in which it undergoes a chemical change.
Select the chemical changes from the following list of changes
Rotting of eggs.
Select the chemical changes from the following list of changes
Drying of a fruit
What is the difference between dissolution of sugar and burning of sugar ?
Fill in the blanks in the following statements using the words given in the box.
| rusted, colourful, substance, chemical, physical, reversible, iron oxide, object |
- Making sugar solution is a ______ change.
- A physical change is generally ______.
- Grinding of wheat grain changes its size. It is a ______ change.
- Iron benches kept in lawns and gardens get ______. It is a ______ change because a new ______ is formed.
Give two examples for the following case:
Physical changes which are reversible
Iron pipes coated with zinc do not get rusted easily.
