In very simple terms, fire can be defines as a source of heat and light energy given out from a chemical reaction. Fire is created when oxygen combines with a combustible material at a high temperature (Eg. Carbon in wood burns at around 325'C). All three ingredients, oxygen, combustible material, and high temperatures are essential to make a fire. Hence fire is neither liquid nor solid or gas. It is a chemical reaction which gives out heat and light energy. Sometimes we talk about liquid fire but it is a misnomer.
Actually when substances with very high melting points melt, they give out an orange glow. For example when iron is molten and is purified and alloyed to form steel, it looks a bright orange colour which resembles fire. However, this is not fire. Due to the high temperatures, the heat energy and light energy that are emitted make it look like fire. When there is fire, certain by-products are formed which are gaseous in nature. For example, carbon in wood and char coal burns to give out carbon di-oxide which is gaseous.
Hence we can write the equation as
C + O2 = CO2 + Energy
This energy is in the form of heat and light which we call fire.
Actually when substances with very high melting points melt, they give out an orange glow. For example when iron is molten and is purified and alloyed to form steel, it looks a bright orange colour which resembles fire. However, this is not fire. Due to the high temperatures, the heat energy and light energy that are emitted make it look like fire. When there is fire, certain by-products are formed which are gaseous in nature. For example, carbon in wood and char coal burns to give out carbon di-oxide which is gaseous.
Hence we can write the equation as
C + O2 = CO2 + Energy
This energy is in the form of heat and light which we call fire.