Comments by "EebstertheGreat" (@EebstertheGreat) on "The Hidden Science of Fireworks" video.

  1. Except for pure copper metal, copper is normally in either the +1 or +2 oxidation state. Copper(I) ions are blue in solution, but Copper(II) ions are blue-green. So the reason the color in your flame test started greener might be that most of the copper was incompletely oxidized. EDIT: Copper(II) chloride has a green flame due to the chloride ion, which is why that firework was green. You wouldn't see that in a flame test of pure copper.
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  2.  @brusicor02  Pure copper metal burns in air with a blue flame. Like the video shows. There is no chloride in air. The species you are seeing are presumably Cu₂O and CuO.
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