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प्रश्न
Define a chemical change. Give two examples of the above changes.
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उत्तर
A permanent change in which new substances are formed whose composition and properties are completely different from those of the original
substances.
Chemical change:
(i) Burning of wood.
(ii) Breathing.
संबंधित प्रश्न
Classify the following as chemical or physical change:
Making a fruit salad with raw fruits
Changes in which only ______ properties of a substance change are called physical changes.
Fill in the blank.
Heat is .................... by a gas during the process of condensation.
Write true or false for the statement
A natural change can also be a desirable change
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Give two examples of periodic changes
Classify the following changes as physical or chemical: curdling of milk
State four differences between physical and chemical changes.
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.
Write true or false
A natural change can also be a desirable change.
A physical change is temporary. Explain.
Give the main differences between physical changes and chemical changes.
Fill in the blank.
The reaction in which energy is evolved is called
What will you take into account while identifying the following?
A chemical change in a substance.
Name the following.
A form of energy required for a chemical change.
Name the following.
The gaseous product of the chemical change which takes place during respiration in living organisms.
When ice melts to form water, change occurs in its
Assertion: The explosion of fire cracker is a physical change.
Reason: A physical change is a reversible change.
Which of the following is a physical change?
Give two examples for the following case:
Physical changes which are reversible
Cutting a log of wood into pieces is a chemical change.
