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प्रश्न
Define physical change. Give two examples for the above changes.
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उत्तर
Physical change: A temporary change in which no new substance is formed, the composition of substance remains the same, though its state, shape and size may change.
Example of physical change:
- Change of water into its vapours.
- Heating of iron rod.
संबंधित प्रश्न
Classify the following as chemical or physical change:
Making a fruit salad with raw fruits
Write true or false for the statement.
Burning of paper and formation of curd are reversible changes
State whether the following is physical or chemical changes.
respiration in living beings —
Write true or false
Rusting of iron is a chemical change.
True or false
Change of seasons is a non-periodic change.
Classify the following changes as physical or chemical.
Fill in the blank.
The process of a liquid changing into a solid is called ________
Read the paragraph and note down the various types of changes it mentions.
It was nearing six o'clock in the evening. The sun was setting. A breeze was blowing. Leaves on the tree were shaking. Sahil was sitting in the courtyard, rolling balls of wet soil, and shaping them into various toys. Then he felt hungry and went into the house. Mother made a dough from wheat flour and fried purees. While eating hot purees, his attention was drawn outside the window. It had started raining. There was lightning, too. Sahil was enjoying his dinner in the dim light.
Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
State the conclusions which can be drawn, to represent photosynthesis as a physical or a chemical change.
Compare the energy changes involved during a physical and a chemical change.
Give a reason why – Heating a platinum wire is a reversible change but, heating a magnesium wire is an irreversible change.
Select the chemical changes from the following list of changes
Boiling of milk.
Select the chemical changes from the following list of changes
The carbon cycle.
State which of the following 1 to 5 pertain to – A: Physical Change B: Chemical change :
- Sublimation.
- Fermentation.
- Liquefaction or condensation.
- Magnetization.
- Respiration.
Give the reason why the following is considered as chemical changes.
A bright light is seen evolved when a strip of magnesium is heated.
Give the reason why the following is considered as chemical changes.
An iron nail kept open in the atmosphere rusts.
Digestion of food is a physical change.
Tearing of sheet of paper into pieces is ______ By the process of Heating of water, change.
Give two examples for the following case:
Physical changes which are reversible
The change of state of a substance from solid to liquid and liquid to gas is ______.
