Flame Tests Tutorial
- A flame test is performed by introducing a sample into the blue flame of a bunsen burner and noting any change in the colour of the flame.
- Flame tests can be used to detect the presence of some metallic elements in salts.
- The heat of the bunsen burner's flame causes electrons in the element to move from their lower energy ground state to a higher energy excited state.
When these excited electrons fall back to their lower energy levels, they emit energy in the form of light of a characteristic wavelength which is the colour of the flame we observe.
(see emission (atomic) spectroscopy)
- Flame tests are an example of a qualitative test, that is, they can detect the presence of certain elements.
Flame tests are not quantitative tests, they can not tell us how much of the element is present in the sample.
(see AAS for details of a quantitative test)