Three things are needed to burn

Combustibles, oxidants and sufficient ignition energy together constitute the combustion conditions. Without any one of these, the fire cannot last.

Why does it glow and heat?

Chemical energy is released when reactants are converted into more stable products. The light emitted by high-temperature molecules and excited particles makes up the flames we see.

Flame color reveals information

Temperature, fuel composition, and metal ions all affect flame color. The flame color reaction in the laboratory uses the characteristic light emitted by different elements to identify them.