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प्रश्न
Why is heat energy needed to melt a solid ? What is this heat energy called ?
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उत्तर
Heat energy is needed to melt a solid because heat energy increases the kinetic energy of particles, which is sufficient enough to break the attraction or bond between the particles and they start moving faster. As a result, there is a change in the state of matter from solid to liquid.
This heat energy is called latent heat of fusion.
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संबंधित प्रश्न
A liquid can change into vapour state at all temperatures.
Explain why in hot summer days water remains cool in earthen pots.
Why does all the water of the earth not get evaporated during hot summer days ?
Why are we able to sip hot tea or milk faster from a saucer rather than from a cup ?
What is evaporation ? State the various factors which affect evaporation.
Which of the following are also considered to be the states of matter ?
- Plasma
- Platelets
- BEC
- BHC
During summer days, water kept in an earthen pot (pitcher) becomes cool because of the phenomenon of :
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 ?
Why is the air in a region dry?
The process of evaporation is not a good technic to separate salt from seawater give a reason.
