Enter Quantum Physics

What determines which emission lines an element or compound possesses? It’s simply the quantum mechanics of the spacing between the different energy levels inherent to the substance itself.

As applied to fireworks, there are a great variety of elements and compounds that can be utilized to emit a wide variety of colours. Different compounds of Barium, Sodium, Copper and Strontium can produce colours covering a huge range of the visible spectrum, and the different compounds inserted in the fireworks’ stars are responsible for everything we see.