How is A flame test related to fireworks streetlights advertising signs and lasers?

A flame test is used to identify the presence of specific metal ions based on the color they emit when heated. This principle is applied in fireworks, where different metal salts produce vibrant colors like red (strontium) and green (barium). Similarly, streetlights and advertising signs often use colored lights created by specific gases or phosphors that emit distinct colors, much like the flame test. Lasers also utilize specific wavelengths of light, with certain gases or materials producing specific colors corresponding to the energy levels of electrons, similar to the emissions observed in a flame test.