Difference between revisions of "Flame test"
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Revision as of 10:31, 4 August 2015
A flame test is an analytical procedure that can determine the presence of certain elements.
A flame test is carried out by placing a sample on a clean wire (commonly made out of platinum or nichrome), and placing it in a hot non-luminous flame (one that does not exhibit black-body radiation).
Potassium (masked easily)
Arsenic, selenium, cesium, lead
Ytterbium metal powder
Boron, tellurium, thallium
Phosphates with sulfuric acid
Sodium (masks everything, invisible through blue glass)
Calcium (greenish through blue glass, green through green glass, masked by barium)
Strontium (violet through blue glass, yellowish through green glass, masked by barium)
Lithium (violet through blue glass, invisible through green glass, masked by barium)
A mad scientist with a more technical bent can improve this technique by building a simple spectroscope, which decomposes the light from the flame into a spectrum. The advantages of spectroscopy is that it does not require any colored glass, all spectral lines are visible separately without them.