Flame reaction of metals. The simple principle of the flame reaction is that the metal salt releases the energy produced by the combustion in the form of light. When part of the salt is burned, electrons outside the nucleus of the metal absorb energy and jump from the lower orbital to the higher orbital. This process is unstable and reversible. When the electrons return from the higher orbital, the excess energy is released again as light. And different metal salts give off different wavelengths of light, which are reflected in different colors to the naked eye. Therefore, by adding different metal salts to fireworks, they will appear different colors as they burn.
Red fireworks generally add strontium salt and calcium salt; Yellow fireworks mainly add sodium salt; Potassium salt and lithium salt are mainly added to the purple fireworks; Green fireworks mainly add copper salt and barium salt. The flame color reaction of different metal salts, combined with the brilliant white light when the brightening agent aluminum powder and magnesium powder burns, so that our fireworks finally show a brilliant color.
What are fireworks made of?
The chemical composition of a complete firework is mainly composed of oxidizer, fuel, color agent and brightening agent. Oxidant plays the role of combustion aid, oxidation and heat release, mainly nitrate and chlorate, etc. Combustible materials mainly include carbon powder, sulfur, etc., which mainly plays the role of combustion and energy supply; Color development agent is mainly composed of some metal salts such as sodium salt, copper salt, barium salt, etc., is also the main source of fireworks color; The purpose of the brightening agent is to make the fireworks more bright and gorgeous, mainly using magnesium powder and aluminum powder when burning bright white light.