My Science School

               Anyone who reads comics must have heard of Superman, and the planet he hails from. Superman comes from a fictional planet called Krypton and an imaginary element called kryptonite is his celebrated weakness. Now, our element krypton has nothing to do with either of them. It is one of the rarest gases on Earth.

               Sir William Ramsay, a Scottish chemist, and his student Morris Travers, an English scientist, discovered krypton in 1898. The element has neither colour nor smell. It does not react with any element other than fluorine gas.

               A type of krypton has a line in its atomic spectrum, and it was used as the standard measure of length from 1960. One metre was defined as exactly 1,650,763.73 wavelengths of this line. This continued to be the standard of measurement for 23 years. But, now the definition has changed.

               Since the element is rare, and expensive, its utility is very limited. The gas is often used in incandescent lamps. It extends the life of the tungsten filament that glows in the bulb when the gas is injected into the lamps. The atomic number of krypton is 36, and the symbol is Kr.

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