Sir William Ramsay added a whole new group to the periodic table

Sir William Ramsay, the Scottish chemist who discovered several noble gases, is the subject of today’s Google doodle. The noble gases are a group of chemical elements with very low reactivity. They have a wide range of uses, as refrigerants and anaesthetics, in lighting and MRI scanners to name a few.

Born in 1852, Ramsay worked in Glasgow and Bristol before moving to University College London, where he carried out his most celebrated work.

In 1894, Ramsay heard a lecture by Lord Rayleigh at the Royal Society, in which he reported that nitrogen isolated from the air had a higher density than nitrogen prepared from chemical sources.

Rayleigh thought this was because of a light impurity in the chemically produced nitrogen, but Ramsay believed there might be an unrecognised new element in the air. The periodic table devised by Dmitri Mendeleev in 1869 had only seven groups, but Ramsay suspected the new element may belong to a hitherto unknown eighth group.

Rayleigh and Ramsay both sought to isolate this new element, working separately but communicating almost daily about their findings. Later that year, they jointly announced the discovery of argon, named after the Greek word for lazy because of its unreactive quality.

Helium, the lightest noble gas, had shown up in spectroscopic observations of the sun and stars, but was first discovered on Earth by Ramsay in 1895. Looking for sources of argon, Ramsay treated the mineral cleveite with acid, and saw the same spectral line while studying gas given off by the reaction. “The excitement of the discovery was so great that Ramsay was obliged to voyage to Iceland for a long rest,” an obituary records.

He suspected there were more inert gases filling the corresponding spaces above and below argon in the periodic table, and went looking for them by fractional distillation of liquid air or liquid argon. In 1898, he reported the discovery of three more elements: neon, krypton and xenon. Ramsay received the Nobel prize in chemistry in 1904 for his work on elucidating the noble gases.

“To him science owes a priceless debt for investigations which, in the short space of a score of years, made an unparalleled contribution, in that they revealed to the world a whole group of hitherto unknown elements possessing properties both unexpected and unique,” the US chemist Theodore Richards wrote after his death in 1916.