The method of spectroscopy was instrumental in the discovery of some elements. Spectroscopy is the process of analyzing light produced when an element is heated. Each element produces a different light when heated.
The spectrum of an element consists of a series of coloured lines. In many cases, the amount of an element present in a sample is too small. But, the element is much easier to detect by spectroscopy.
Caesium was discovered using spectroscopy by two German scientists, Robert Bunsen and Gustav Kirchhoff. It happened in 1859. Bunsen and Kirchhoff discovered caesium while they were busy studying a sample of mineral water taken from a spring.
At first, they identified the spectral lines for sodium, potassium, lithium, calcium, and strontium; these elements were well-known at that time. After removing these elements from the sample, they could still see two blue lines in the spectrum.
This was due to the presence of caesium. It was Bunsen who suggested calling the element caesium; it is derived from the Latin word for ‘sky blue’.
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