The second method by which light and color is produced in fireworks is atomic and/or molecular excitation followed by emission of light. This is the same process that produces the interesting colors we see in neon signs as shown in the image above. Different elements and molecules will emit their own specific colors of light after they are excited by high levels of electrical energy (as in the neon signs) or heat energy (as in the fireworks). For example, sodium is a very strong emitter of yellow light. This can sometimes be seen by putting ordinary table salt (sodium chloride) into a candle flame. Sodium emission due to electrical excitation is also what produces the saturated yellow colors seen in some street lights and parking lot lights in large cities.
A variety of atoms and molecules are