Question

.Give reasons for the following:[5](a)A matchstick can light a tiny splinter of wood but not a big log of wood.(b)Forest fires occur during the hottest summer days.(c)Dry leaves catch fire easily but it is difficult toburn a heap of green leaves

Answer 1

1.

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 and can light it while a big log of wood has an higher ignition temperature.

2.

During hot summers, the hot air blows which increase the friction between the dry leaves and trees and thus lead to fire as they rub against each other.

3.

Green leaves contain moisture whereas dry leaves do not contain  moisture as a result, the ignition temperature of green leaves is higher than that of dry leaves. Due to this reason, it is difficult to burn a heap of green leaves but dry leaves catch fire easily.

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@payal