How can flame color identify an unknown metal?
How can a spectrum positively identify an element?
How can astronomers tell which elements a star contains without a sample of it?
The flame test is used to visually determine the identity of an unknown metal or metalloid ion based on the characteristic color the salt turns the flame of a bunsen burner.
In emission spectra, bright lines will show up corresponding to the difference between energy levels of the elements, where in an absorption spectrum, the lines will be dark.
By passing starlight through a prism and examining the resulting spectrum, they found absorption
