Unlike other gases such as oxygen or chlorine, neon is an extremely unreactive, odourless and colourless gas. Due to its very stable and unreactive nature, Neon was hence very hard to discover, and even using modern techniques remains difficult to detect.
The ascertainment of this very inert gas is attributed to Sir William Ramsay (1852 - 1916), a Scottish chemist who hypothesized that just like helium and krypton which had been discovered previously, other unreactive gases existed in nature.
Neon was discovered through the use of a method that is now aptly described as the 'air liquefaction technique'. In this, Ramsey collected thirty tons of air, cooled the air to a liquid and then left the liquid in room temperature. The liquid rapidly vaporises according to its boiling point, however, different elements have different boiling points due to the different intermolecular forces.
Consequently, the gases vaporise at different time intervals, and can then be collected separately. This air liquefaction technique is still a popular method of distilling and separating fractions of air. Indeed, the current modern method for collecting and separating Neon gas is based on this technique.
It is interesting to note that from the liquefaction of thirty tonnes of air, less than a kilo of Neon is produced. This is because Neon is one of the rarest gases found in the Earth's atmosphere. Nonetheless, despite the rarity of this gas, it is used abundantly in the electronics and lighting industries. This is because when a high voltage is passed through neon gas, it glows a fluorescent and attractive red colour.
In conclusion, the discovery of neon was perhaps the most difficult elemental discovery ever achieved. Neon is extremely hard to detect due to its stability, rarity and the fact that it is both colourless and odourless. The neon industry is experiencing an immense surge, and this can be attributed both to its attractive appearance in neon lights and signs, and also its immense potential that we are only on the verge of discovering. .