Page 43 - Genius Kidz Prudence Learning Sc-8

(hydrocarbons made from crude oil) Zone of complete combustion.

Wax (Solid form) ¾¾® Liquid wax ¾¾® Non-luminous zone.
Vaporized wax + supporter of combustion (O ) Blue coloured zone.
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¾¾® Flame generated (b) Middle zone :

Zone of a candle flame Luminous zone.
Candle flame consists of three zones : Zone of incomplete combustion.

(a) Outer zone It is moderately hot.
(b) Middle zone Unburnt carbon particles and carbon

monoxide are left behind due to
Outer zone of
Hottest complete
part combustion (blue) incomplete combustion.
Moderately Unburnt carbon particles impart yellow
hot Middle zone of
partial combustion colour to the flame.
Least (yellow)
hot Black soot is left on the objects that
Innermost zone of
unburnt wax come in contact with this zone.
Wax candle vapours (black)
(c) Innermost zone :
Different zone of candle flame
Made up of wax vapours only.
(c) Innermost zone
No combustion in this zone due to
(a) Outer zone : absence of oxygen. So, it is a zone of no
Faintly visible zone. combustion.

Hottest zone. It is a dark zone present around the wick
of a candle.

Activity 3

Find out why the blue zone is the zone of complete combustion.
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Food is fuel for the body. During cellular respiration the glucose obtained from food is burnt to form carbon dioxide
and water and energy is given out.

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