Answer:
(a) Evaporation produces
cooling as the particles at the surface of the liquid gain energy from the
surroundings and change into vapour, thereby producing a cooling effect.
(b) Air around us cannot hold more than
a definite amount of water vapour al a given temperature which is known as
humidity. So, if the air is already rich in water vapour, it will not take up
more water; therefore, rate of evaporation of water will decrease.
(c) A sponge has minute holes in which
air is trapped. Also the material is not rigid. When we press it, the air is
expelled out and we are able to compress it.
(d) Ice is solid at 0°C because it has
a definite volume and definite shape due to strong intermolecular forces. Water
is liquid at room temperature because it has definite volume and no definite
shape due to weak intermolecular forces of attraction.
(e) Sugar crystals dissolve faster in
hot water than cold water because hot water molecules contain more kinetic
energy. Due to this, they strike faster on the particles of sugar than cold
water molecules. As a result, hot water will
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