Chapters
Chapter 2 - Microorganisms : Friend and Foe
Chapter 3 - Synthetic Fibres and Plastics
Chapter 4 - Materials : Metals and Non-metals
Chapter 5 - Coal and Petroleum
Chapter 6 - Combustion and Flame
Chapter 7 - Conservation of Plants and Animals
Chapter 8 - Cell - Structure and Functions
Chapter 9 - Reproduction in Animals
Chapter 10 - Reaching the Age of Adolescence
Chapter 11 - Force and Pressure
Chapter 12 - Friction
Chapter 13 - Sound
Chapter 14 - Chemical Effects of Electric Current
Chapter 15 - Some Natural Phenomena
Chapter 16 - Light
Chapter 17 - Stars and the Solar System
Chapter 18 - Pollution of Air and Water
Chapter 6 - Combustion and Flame
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List conditions under which combustion can take place.
Fill in the blanks:
Burning of wood and coal causes _______ of air.
Fill in the blanks:
A liquid fuel used in homes is _________.
Fill in the blanks:
Fuel must be heated to its __________ before it starts burning.
Fill in the blanks:
Fire produced by oil cannot be controlled by ________ _
Explain how the use of CNG in automobiles has reduced pollution in our cities.
Compare LPG and wood as fuels.
Give reasons
Water is not used to control fires involving electrical equipment.
Give reasons
LPG is a better domestic fuel than wood.
Give reasons.
Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.
Make a labelled diagram of a candle flame.
Name the unit in which the calorific value of a fuel is expressed.
Explain how CO2 is able to control fires.
It is difficult to burn a heap of green leaves but dry leaves catch fire easily. Explain
Which zone of a flame does a goldsmith use for melting gold and silver and why?
In an experiment 4.5 kg of a fuel was completely burnt. The heat produced was measured to be 180,000 kJ. Calculate the calorific value of the fuel.
Can the process of rusting be called combustion? Discuss.
Abida and Ramesh were doing an experiment in which water was to be heated in a beaker. Abida kept the beaker near the wick in the yellow part of the candle flame. Ramesh kept the beaker in the outermost part of the flame. Whose water will get heated in a shorter time?