Match the items of column I with items of column II. Column I Column II (a) Oxides of sulphur and nitrogen (i) Fire extinguisher (b) CNG (ii) Incomplete combustion of coal (c) Oxygen (iii) Very low ignition temperature (d) Inflammable substance (iv) Acid rain (e) Carbon dioxide (v) Necessary for combustion (f) Carbon monoxide (vi) Fuel for automobile

Oxides of sulphur and nitrogen are responsible for acid rain. It is extremely harmful to forests. These can dissolve nutrients in the soil. CNG is used as a fuel for automobile. It can be used as a replacement for gasoline. It has advantages in environmental and pollution control since it is a cleaner source of energy. Oxygen is necessary for combustion. Fuel reacts with it and forms oxides in this chemical process. Inflammable substance has very low ignition temperature. These can catch fire very easily. Petrol and acetone are examples of these type. Carbon dioxide is an excellent fire extinguisher. It has more density than air so it forms a layer around the burning substance so it cuts off the supply of oxygen. Carbon monoxide forms due to incomplete combustion of coal. It is toxic to the animals that use haemoglobin as an oxygen carrier. Column I Column II (a) Oxides of sulphur and nitrogen (iv) Acid rain (b) CNG (vi) Fuel for automobile (c) Oxygen (v) Necessary for combustion (d) Inflammable substance (iii) Very low ignition temperature (e) Carbon dioxide (i) Fire extinguisher (f) Carbon monoxide (ii) Incomplete combustion of coal

Match the items in column I with the items of column II. Column I Column II (a) LPG (i) Non-combustible (b) Iron nails (ii) Deforestation (c) Candle (iii) Cooking gas (d) Wood (iv) Flame

LPG is used as a cooking gas. It mainly contains propane and butane. It burns more cleanly compared to petrol and is free from particulate matter. Iron nails are non-combustible substance. These are the substances which do not burn in the presence of oxygen or air. Candle forms flame on burning. It is formed when the material vaporises in this process. Wax reacts with oxygen in the air to produce carbon dioxide. Deforestation is occurred due to the cutting of trees for wood. This used as fuel in villages because of its easy availability and cheap rates. Column I Column II (a) LPG (iii) Cooking gas (b) Iron nails (i) Non-combustible (c) Candle (iv) Flame (d) Wood (ii) Deforestation

Match the following for the flame of the candle. Column I Column II Column III (a)Hottest part (i)Innermost zone of unburnt wax vapours (x)Blue (b)Moderately hot (ii)Middle zone of partial combustion (y)Black (c)Least hot (iii)Outer zone of complete combustion (z)Yellow

The hottest part of the flame is the outermost zone with complete combustion having blue colour. This zone is used by goldsmith for their work. Moderately hot part of the flame is the middle part of it having partial combustion and it is yellow colour. It is the luminous zone. It consists of soot particles. Least hot is the innermost zone of unburnt wax vapours which are black. The movement of molten wax up away from the wick is due to phenomena called capillary action. Column I Column II Column III (a) Hottest part (iii) Outer zone of complete combustion (y)Blue (b)Moderately hot (ii) Middle zone of partial combustion (z)Yellow (c) Least hot (i) Innermost zone of unburnt wax vapours (x)Black

E M B I B E

All in One - SCIENCE CBSE Class 8>Chapter 6 - Combustion and Flame>Chapter Practice>Q 12

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8th CBSE

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Sun produces heat and light due to nuclear reactions.

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Important Questions on Combustion and Flame

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8th CBSE

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All in One - SCIENCE CBSE Class 8>Chapter 6 - Combustion and Flame>Chapter Practice>Q 13

The fuel can be in solid, liquid or in gaseous form.

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8th CBSE

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All in One - SCIENCE CBSE Class 8>Chapter 6 - Combustion and Flame>Chapter Practice>Q 1

Match the items of column I with items of column II.

Column I	Column II
(a) Oxides of sulphur and nitrogen	(i) Fire extinguisher
(b) CNG	(ii) Incomplete combustion of coal
(c) Oxygen	(iii) Very low ignition temperature
(d) Inflammable substance	(iv) Acid rain
(e) Carbon dioxide	(v) Necessary for combustion
(f) Carbon monoxide	(vi) Fuel for automobile

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8th CBSE

IMPORTANT

All in One - SCIENCE CBSE Class 8>Chapter 6 - Combustion and Flame>Chapter Practice>Q 2

Match the items in column I with the items of column II.

Column I	Column II
(a) LPG	(i) Non-combustible
(b) Iron nails	(ii) Deforestation
(c) Candle	(iii) Cooking gas
(d) Wood	(iv) Flame

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8th CBSE

IMPORTANT

All in One - SCIENCE CBSE Class 8>Chapter 6 - Combustion and Flame>Chapter Practice>Q 3

Match the following for the flame of the candle.

Column I	Column II	Column III
(a)Hottest part	(i)Innermost zone of unburnt wax vapours	(x)Blue
(b)Moderately hot	(ii)Middle zone of partial combustion	(y)Black
(c)Least hot	(iii)Outer zone of complete combustion	(z)Yellow