Page 42 - Genius Kidz Prudence Learning Sc-8

(ii) Processed fuels : Fuels that are FLAMES
obtained from natural fuels are called Flame is generated by those combustible
processed fuels. These are also called substances which vaporize on heating, for

secondary fuels. Examples are charcoal, example, candle wick. Coal or charcoal do not

coke, petrol, diesel, etc. generate a flame??
Fuel as a pollutant Suzi : Because coal or

Fuel burning can be really hazardous because charcoal doesn't
of the following : vaporize, are only

(a) Suspended particulate matter : Ash and s u p p o r t e r o f
unburnt carbon particles released during combustion i.e.
fossil fuel burning form suspended oxygen is gaseous.
particulate matter or SPM. So, no flame is
generated only a glow.
SPM Effects :
Jack : Ok ! I got now! The combustible
Reduces visibility
substance and supporter of
Spoils clothes
combustion both must be in gaseous
Causes respiratory diseases. state for flame to rise.

Forms smog (smoke + fog). Suzi : Yes !!
(b) Greenhouse effect : Increased production Flame of Candle
of greenhouse gases such as carbon Candle consists of Þ Wax + Wick

dioxide results in increase of temperature
(Natural wax produced in the behive)
of earth. This effect is called greenhouse
effect. The wax serves as a fuel. It is usually a
hydrocarbon made from crude oil. The wick is
Effects of increase in greenhouse gases :
made of a material that absorbs liquids such as
It results in melting of polar ice caps,
water or molten wax.
which, in turn, results in flooding of
Wax can be : Beeswax
coastal regions.
Soya (produced form of soybean oil)
(c) Carbon monoxide : Incomplete combustion
adds carbon monoxide to the atmosphere. It Plant wax (wax secreted by plants)
is a highly poisonous gas. Or paraffin or paraffin + plastic can be used.

(d) Acid Rain : Nitrogen and sulphur resulting
due to incomplete combustion add up in the
atmosphere and react with oxygen to form
nitrogen and sulphur dioxides which, in turn,
dissolve in rain water to form acid rain.

Effects of Acid Rain :

! It causes harm to vegetation and
animals.

! It damages the buildings. Different type of candles

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