FORM 1 7.2 COMBUSTION

Three conditions needed for combustion

• Petrol, oxygen, fire

• Petrol, paper, fire

• Petrol, wood, fire

Why the candle flame is extinguished when the boy blow?

• The saliva from the boy put off the flame

• The oxygen is removed from the flame

Why do we use water to extinguish fire?

• To removed the oxygen

• To removed the fuel

• To removed the heat

what is the best way to extinguished the fire?

• water

• foam

• fire blanket

How does the fire blanket work?

• To reduce the heat and eventually extinguish the fire

• To reduce the oxygen and eventually extinguish the fire

• To reduce the fuel and eventually extinguish the fire

Metals like potassium and sodium are kept in paraffin oil. Why?

• Potassium and sodium metals are flammable when exposed to heat.

• Potassium and sodium metals are flammable when exposed to fuel.

• Potassium and sodium metals are flammable when exposed to air.