We will understand the process of combustion, ignition temperature, and why oxygen is needed for combustion. Some objects catch fire quickly while other objects take time. It depends on its ignition temperature. We will also learn about different types of combustion such as Rapid Combustion, Spontaneous Combustion, and Explosive combustion. Lately in the chapter, we will learn about the three different zones of the flame which are the dark zone, the luminous zone, and the non-luminous zone.

A chemical process in which a substance reacts with oxygen to give off heat is called combustion. The substance that undergoes combustion is called combustible. It is also called fuel. The fuel could be solid, liquid, or gas. During the process of combustion, heat and light is produced, and Oxygen is required to keep burning any substance

The lowest temperature at which a substance catches the fire is called its ignition temperature. Until the temperature of an object reaches up to its ignition temperature, it does not catch fire. The paper cup does not catch the fire because the water inside the cup stops the paper from reaching its ignition temperature.

Do you know how fire is controlled when it breaks out in a certain place? Firefighters spray a lot of water. Water cools the combustible material so that its temperature is brought below its ignition temperature. This prevents the fire from spreading. We will also learn how fire extinguishers are used in different situations to control fire.

There are several types of combustion. Rapid combustion is when the gas burns rapidly and produces heat and light. When a material suddenly bursts into flames, without the application of any apparent cause, is called Spontaneous Combustion.  When a material bursts suddenly to produce heat, light, and sound on the application of heat or pressure, it is called Explosive combustion.

Have you ever noticed the flame of the burning candle? There are 3 parts of the flame. The first one is the outermost part which is non-luminous. The hottest part and has a blue color in the flame. This part has an unlimited supply of oxygen. Thus, complete combustion takes place here.