Why does the fire always rise when it burns?

Although it has been used regularly for a long time, the fact that the flame burns always upward cannot be explained by everyone.

We need to first understand the nature of fire, an important invention that sets humans apart from other species. It is difficult to imagine what human society would be like without fire.

Why does the fire always rise when it burns?
Humans use fire skillfully.

Matter is made up of billions of atoms, and has always stayed that way. Fire is not like that: fire can change into other forms – it is part of chemical reactions .

Flames are caused by chemical reactions between oxygen in the air and fuel or combustible materials.

However, the condition of the reaction to occur is that there must be an impact to make the combustible reach the burning point. This action can be either rubbing or thermal impact. Then the combustion reaction takes place and we have a flame.

Why does the fire always rise when it burns?
The three elements that make up the fire.

The combustion reaction gives off a lot of heat. That is what sustains the fire, and causes it to spread.

The heat generated by that combustion maintains the material at the ignition temperature, so that combustion continues until there is nothing left to burn or until human intervention is reached.

In addition to heat, the accompanying burning reaction shines. The color of the flame depends on the material burned, and how hot the flame is. Uneven color in the flame is caused by temperature inhomogeneity.

Watch the video explaining why the flame is pointing upwards:

A characteristic of burning is that the flame is always directed upwards. Why is that?

Explanation: In fact, the fact that the flame always points upwards is a result of the movement created by the air during combustion (convection).

Why does the fire always rise when it burns?
Convection causes the flame to always point upwards.

The air around the flame is heated because the density of the hot air is less than that of the cold air, the hot air rises upwards and the cold air element will fill in for additional replacement.

As the hot air flows upward, the flame will be drawn upwards. When burning a large fire, the amount of hot air is very large, and the cold air rushes in very quickly, making the fire stronger.

Why does the fire always rise when it burns?
Come on up!

In addition, because combustion is a chemical reaction with the participation of oxygen, gases will be produced after the reaction such as CO 2 , NO 2 … (smoke).

They have a lighter density than air (including many gases such as oxygen, nitrogen …) so they will be above those gases, moreover in high temperature areas, the pressure is also higher than other places.

In fact, the air flow is influenced by many factors, so the movement flow is always disturbed. It affected the movement of hot gas, making the flame unstable.