Mrs. Khanna was making breakfast in kitchen. For this purpose she was heating water in a pan. In the meantime, her 12 years old son, Pappu entered the kitchen and saw the water vapour coming out from the pan. Pretend yourself to be Mrs. Khanna and answer the following questions: (𝒊) What is the process going on in the pan? (𝒊𝒊) Why was this process occurring? (𝒊𝒊𝒊) Give one way by which Pappu can relate this phenomenon with his everyday life. (𝒊𝒗) What values are shown by Pappu?

Question

Rifat Afreen · Accepted Answer

(i) Evaporation of water.
(𝑖𝑖) The water absorbs heat from the burner and the water molecules keep changing their energies due to molecular collisions as a result of which some molecules at the surface of the liquid acquire sufficient energy and escape.
(𝑖𝑖𝑖) During summer season Pappu wears cotton clothes and perspires more. The heat energy required for evaporation is absorbed from the body leaving the body cool. In this way he relates evaporation with his day to day life.
(𝑖𝑣) Curiosity, observatory skills.

Substance	Melting point(°C)	Boiling point(°C)
X	-219	-183
Y	119	445
Z	-15	78

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