Flame tests

Flame tests

 

Different chemicals glow in characteristic colours when put into a flame of a Bunsen burner. Here salts of various metals have been used (from left to right) copper, lithium, strontium, sodium, barium and potassium. The colour comes from metal atoms as they gain energy from the flame, then release the energy as light of specific colours. One use of this effect is the manufacture of coloured fireworks. Perhaps more importantly, this phenomenon is the basis of flame emission spectroscopy, an analytical technique used in forensics and medicine to detect tiny amounts of metals.

Image © Science Photo Library

 

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