Argon, discovery spectrum

In 1898, Ramsay and Travers were studying the minute amount of gas that remained after oxygen, nitrogen, and argon had been removed from air. They heated the sample of gas and studied the spectrum produced by it. Ramsay and Travers found spectral lines they had never seen before. They described their discovery ... 

As mentioned, argon was the first noble gas to be discovered, but helium was in fact known 26 years before the discovery of argon. The French astronomer Pierre J. C. Janssen (1824-1907) studied a total solar eclipse in India in 1868. A yeUow line D3, not coincident with sodium s doublet, was observed. Neither did the Hne emanate from hydrogen or any other known element, as was proved by the British astronomer Sir Norman Lockyer (1836-1920). Thus there was an element in the sun that was not known on earth. It was named helium due to its origin in the sun. Many spectrum analysts did not accept the new solar element. However, in 1876, John W. Draper, the first president of the American Chemical Society, made an inspired statement [51.1] ... 

Eventually they forced themselves to examine the spectrum of the new element. They observed many characteristic lines in the visible wavelength region. A new gas had been discovered. A name. Ramsay asked his thirteen-year-old son for a proposal. He answered promptly novum because it is new. The proposal fell onto fertile ground, but the name was changed to neon, also meaning new but more adapted to the names argon and krypton. The discovery was made in June, 1898. They were satisfied with its atomic weight - the value was 20. 

Before the discovery of argon, some lines in the spectrum of the sun were ascribed to an element not yet known on earth. This element was called helinm (from the Greek helios, meaning sun ). In 1895, Ramsay and the Swedish chemist Per Theodor Cleve (working independently) announced the discovery of helium gas in the mineral cleveite (a uranium ore) by identifying the spectrum of helium. 

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