Name two substance having low ignition temperature and two having high ignition temperatures.

Name the very poisonous gas produced by the incomplete combustion of fuels.

Name the fuel which is gradually replacing petrol and diesel in automobiles.

Fill in the blanks with suitable words:

(a) A fuel must be heated to its……… before it starts burning.

(b)The most common supporter of combustion around us is……………..

(c)Fire produced by burning oil cannot be controlled by…………………….

(d)A liquid fuel used in homes is………

(e)The amount of heat evolved when 1kg of a fuel is burnt completely is called its…………………..

(f)The substance which vaporize during, give…………………..

(g)Burning of wood and coal causes…………….Of air.

What are fuels? Name any two common fuel.