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प्रश्न
True or false
In a physical change no net energy change is involved.
पर्याय
True
False
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उत्तर
True
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संबंधित प्रश्न
Write short answer.
Sublimation is classified as a physical change. Why ?
Make a list of different types of changes with example.
Fill in the blank.
When a candle burns, wax melts. Melting of wax is a ________ change.
Solve this crossword by using the clues that follow-
Across
1. Energy in the form of sunlight is absorbed by the green plants in this process.
4. The reddish-brown substance formed over iron in the presence of oxygen and moisture.
5. This change is permanent and irreversible.
6. The process in which a solid directly changes into gaseous state.
Down
1 . It is the change that takes place in case of swinging pendulum of a clock. –
2. Occurrence of this is a non-periodic change as well as a natural change.
3. It is a physical change.
What is a chemical change ? Give two examples of chemical changes.
Change is the law of nature and occurs in our everyday life, at all times and in all places.
Differentiate between the following change with a suitable example.
Periodic and non-periodic 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.
Select the chemical changes from the following list of changes
Vaporisation of water into water vapour.
Select the chemical changes from the following list of changes
Breaking of glass
A physical change is generally____________.
