Question

combustion. In most cases a very simple thing takes place. Oxygen from the air
The scientific name for burning is combustion. There are different kinds of
combines with some material that can burn. This reaction produces heat. If the
process takes place rapidly, we see flames or an intense glow or actually feel the
combustion, as in an explosion. When wood or paper combines with oxygen, we
have flames.
We also have combustion in the engines of automobiles. Gasoline burns with
oxygen taken from the air. It happens so rapidly that we call it an explosion. At
the opposite end, rusting of iron is a combustion which goes on so slowly that
we may not notice it for years. If the heat that results during a slow combustion
problem cannot escape into the air, the temperature may reach a point where
active burning begins. This is called spontaneous burning. This happens when
oily rags are left in a closed place. The oil undergoes slow oxidation or burning
which results in heat. Since the heat cannot escape, the temperature rises and the
rag bursts into flames.
Oxygen, which is necessary for combustion, is one of the most common elements
in nature. The air that normally surrounds us contains approximately 21 per cent
of
oxygen.
This
oxygen
is forever ready to start a combustion process. note making​

Answer 1

If it was an answer thank you! And if it was a question, I'm sorry I couldn't understand it.