An exothermic reaction is a chemical or physical reaction that releases heat. It gives out net energy to its surroundings. That is, the energy needed to initiate the reaction is less than the energy that is subsequently released
( en.wikipedia.org/wiki/Exothermic_reaction )
Fireworks are en examples of exothermic reactions. To shoot a firework, you light it with fire. A firework is filled with gunpowder, so as it travels upwards, it is delivering either sparks or smoke depending on the type of firework you use. After it reaches it's stopping point in the sky, it ignites like a bomb.. But, instead of dangerous substances.. etc.. it ignites with sparks, so it is beautiful to the eye, yet still insanely loud like a bomb. A firework is an exothermic reaction because it releases heat as it goes up and when it ignites. It is not a physical reaction, it is generic chemical reaction. Above all reactions, fireworks are some of the coolest ones. ( ^ My own knowledge )
