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प्रश्न
Why does our palm feel cold when we put some acetone or petrol or perfume on it?
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उत्तर
- When we put some acetone or petrol or perfume on our palm, it evaporates.
- During evaporation, particles of the liquid absorb energy from the surrounding or the surface of the palm to compensate for the loss of energy, making the surroundings cool.
- Hence, our palm feels cold when we put some acetone or petrol or perfume on it.
संबंधित प्रश्न
State three factors which affect the rate of evaporation of a liquid.
Which produces more severe burns : boiling water or steam ? Why ?
How will you demonstrate that water vapour is present in air ?
How can the evaporation of a liquid be made faster ?
Which of the following are also considered to be the states of matter ?
- Plasma
- Platelets
- BEC
- BHC
The evaporation of water increases under the following conditions :
The scientists now say that there are actually five states of matter A, B, C, D and E. The state A has a fixed volume but no fixed shape. The state B can be compressed very easily by applying pressure and state C has a fixed shape as well as a fixed volume. The state D is a mixture of free electrons and ions whereas state E is named after an Indian scientist and a famous physicist.
- Name the physical states (i) A (ii) B (iii) C (iv) D, and (v) E
- Name one substance belonging to state C which can directly change into vapours on heating. What is this process known as ?
- Name one substance which normally belongs to state B but whose solid form changes directly into gaseous state.
- Name the most common substance belonging to state A.
- Which state of matter makes the sun and other stars to glow ?
How does the water kept in an earthen pot remain cool?
The rate of evaporation ______ with rising temperature.
The rate of evaporation is more when the surface area is greater.
