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प्रश्न
Define physical change. Give two examples for the above changes.
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
Fill in the blank.
A new substance is formed in a ............... change.
State whether the following is physical or chemical changes.
water cycle in nature —
State whether the following is physical or chemical changes.
heating a mixture of iron filings and sulphur—
State whether the following is physical or chemical changes.
cutting wood into small pieces —
Tick (√) the correct alternative from the choice given for the following statement.
An example of both physical and chemical change is
Classify the Following as a Physical Or a Chemical change.
Glowing of an Electric Bulb
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.
Desirable and undesirable change.
State what is meant by the term – interconversion of matter. Is interconversion of matter a physical change or a chemical change.
Give reasons why – separation of mixtures e.g. iron from a mixture of iron and sulphur is a physical change, but heating a mixture of iron and sulphur is considered a chemical change.
Fill in the blank with the appropriate word of the statement given below:
If a change is permanent and irreversible it is considered a _________ change.
Name the following:
The term involved in the change of state from – ‘water to ice’ – which is a physical change.
Name the following:
The type of change physical or chemical involved – ‘when a substance undergoes a change in state, colour or size’.
Give a reason why
Change of seasons is a periodic change while the change of weather is a non-periodic change.
Give a reason why – Addition of zinc nitrate to water is a physical change but, the addition of zinc to dilute nitric acid is a chemical change.
Name the following.
A form of energy required for a chemical change.
Classify the following changes as physical and chemical changes
A rough piece of wood is sanded and polished resulting in change in texture, Rusting of a iron nail, Painting the grill, Bending a paper clip, Pounding silver into thin plate, Rolling the chappathi dough into thin wire, Occurrence of day and night, eruption of volcano, burning of matchstick, dosa from the batter, blinking of eyelids, occurrence of a thunderstorm, rotation of the earth, formation of eclipses.
| Sr. No. | Physical changes | Chemical changes |
| 1. | ||
| 2. |
Assertion: Burning of wood log to charcoal is a physical change.
Reason: The products formed of burning a piece of wood can be easily converted back to wood log.
Paheli’s mother made a concentrated sugar syrup by dissolving sugar in hot water. On cooling, crystals of sugar got separated. This indicates a
A physical change is generally____________.
