Question 1 What is a matchstick?
Question 2 A matchstick does not catch fire and burn on its own.Why?
Question 3 Kerosene oil and wood do not catch fire on their own at room temperature.Why?
Question 4 Can u burn a piece of wood by bringing a lightened matchstick near it.Explain?
Question 5 Cooking oil in a frying pan catches fire when the frying pan is kept over a burning stove for a long time.Explain?
Question 6 A matchstick can light a tiny splinter of wood but not a big log of wood.Why?
Question 7 Coal fire cannot by started by using a lightened matchstick directly?Why?
Question 8 Why do you have to use paper or kerosene oil to start fire in wood or coal?
Question 9 Why forest fires occur during the hottest summer days.Explain?
Question 10 It is difficult to burn a heap of green leaves but dry leaves catch fire easily.Why?
Lightning of matchstick
A matchstick does not catch fire and burn on its own at room temperature because the ignition temperature of matchstick is higher than the room temperature.A matchstick starts burning on rubbing it on the side of the matchbox because the heat produced by friction heats the chemical at the head of the matchstick to their ignition temperature and makes it catch fire.
Kerosene oil and wood do not catch fire on their own at room temperature because the ignition temperature of kerosene oil and wood are higher than the room temperature.If kerosene is heated little it will catch fire easily because kerosene oil has a comparatively low ignition temperature which is reached even on little heating.
If wood is heated a little,it does not catch fire because wood has a higher ignition temperature which is not reached by little heat being supplied to it by a matchstick.
We see cooking oil in a frying pan catching fire when the frying pan is kept over a burning stove for a long time because the cooking oil gets heated to its ignition temperature when kept over a burning stove for a long time.
A matchstick can light a tiny splinter of wood but not a big log of wood.A splinter of wood has a low ignition temperature.A burning matchstick can produce sufficient heat to reach the ignition temperature of the splinter of wood therefore a matchstick can light a splinter of wood directly.
The ignition temperature of log of wood is high and cannot be reached by the small heat produced by a burning matchstick.So,a matchstick cannot light a log of wood directly.In order to burn a log of wood,a small fire is first started by burning straw with a matchstick,and then the log of wood is placed over this fire.Heat of this fire then heats the log of wood to its ignition temperature due to which the log of wood starts burning.
Coal has a high ignition temperature,so a coal fire cannot be started by using a lighted matchstick directly.This is because the small heat produced by burning matchstick is not sufficient to heat the coal to its ignition temperature.A piece of cloth is dipped in kerosene oil and some pieces of cloth is ignited by a lighted matchstick,it starts burning.The heat produced by the burning of kerosene soaked cloth makes the pieces of wood to burn.the coal pieces are then placed over the burning wood pieces.The large heat produced by the burning wood pieces heats the coal to its ignition temperature due to which the coal also starts burning.
The forest fires occur during the hottest summer days.During extreme heat of summer,sometimes the ignition temperature of dry grass in the forest is reached,the fire spreads to bushes and trees,and very soon the whole forest is on fire.
It is difficult to burn a heap of green leaves but dry leaves catch fire easily.The green leaves contain a lot of water.This water does not allow the green leaves to get heated to their ignition temperature and makes burning of green leaves difficult.Dry leaves do not contain water,they get heated to their ignition temperature easily and hence catches fire easily.