For example NaCl burns with yellow-orange colour. So can I find out the elements of the compound using that color(Assuming that I don't know the compound)?

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    $\begingroup$ Yes and no. If you put NaCl into a flame, like I did here, you will get the familiar yellow sodium D lines emission. More generally, though, you need to do spectroscopy, e.g., atomic emission spectroscopy or atomic absorption spectroscopy. Flame tests are too crude and not quantitative. As well, the chlorine from the NaCl will not significantly emit visible light (from excited chlorine atoms de-exciting). And note that sodium is an easy element compared to, e.g., uranium: chemistry.stackexchange.com/a/175028/79678. $\endgroup$
    – Ed V
    Aug 11, 2023 at 15:47
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    $\begingroup$ @EdV I was going to post an answer, but I think you should do it instead. $\endgroup$ Aug 11, 2023 at 16:47
  • $\begingroup$ There are a number of related relevant questions here, and answers too, e.g., chemistry.stackexchange.com/q/168454/79678. Search at this stack exchange for “flame test” and related terms. Several people here, e.g., @AChem, have posted good answers to relevant queries. $\endgroup$
    – Ed V
    Aug 12, 2023 at 19:22
  • $\begingroup$ Some elements give very distinct flame colours. But many do not and distinguishing mixtures by colour is not remotely easy without proper instruments that look at the full spectrum of emission lines in the flame. $\endgroup$
    – matt_black
    Aug 14, 2023 at 10:54
  • $\begingroup$ I wonder what colour osmium + O2 would produce $\endgroup$ Aug 15, 2023 at 3:12


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