Krypton like most Noble gases is odourless, colourless and inert. It was discovered in 1898 by Scottish chemist William Ramsey and his assistant Morris Travers. Ramsey had a track record of discovering Noble gases having discovered helium and argon. He had built up a picture of the gases existing in the same group. Obtaining a sample of air as a liquid they began to evaporate off gases. After removing Nitrogen and Oxygen by heating with Copper and Magnesium, they applied a high voltage to the left over gases and produced a yellow and green spectrum, which had never been seen before. They named the new gas Krypton, from the Greek ‘kryptos’ meaning ‘hidden.’ Krypton as a gas was used as a scientific length between 1960 and 1973 as the measurement of a metre being defined as 1 650 763.73 wavelengths of krypton-86’s orange-red spectral line. Krypton’s main uses are in photography equipment for lighting and in high powered lasers. It is located in Group 18 as a non metal gas which is odourless and colourless. It has a melting point of -157°c and a boiling point of -153°c.
Sir William Ramsey, M.W. Travers