# Effect of the counterion on the colour emitted by a metalic salt

Could someone please enlighten me on what would be the theoretical effect of a counter ion on the colour of the flame emitted by a metallic salt in a flame test? Eg. NaCl - what would be the effect of the non-metal on the general colour of the flame of the compound?

I am looking into specific groups of metallic salts based on 3 metals: Sodium, Potassium and Copper II. I have searched throughout the literature but have not found an answer yet.

You can put in the flame any compound of Sodium, Potassium or Copper. The flame will be colored. But the emitted light will probably be highest with chlorides, because chlorides are more volatile than sulfates, carbonates or any other compounds. In order for the flame to be colored, the substance must first be volatilized, then decomposed into its atoms, then excited by the flame up to an electronic level. And then, on the way back, light is emitted. The first step, the volatilization, is easy with chlorides (maybe also with other halogenides - I don't know). With copper, it seems to be more complicated, because the light can be emitted from copper metal and also from volatile chlorides like $$CuCl$$, before their decomposition. It depends on the temperature.