Only a select few scientists can boast about discovering an element. Among them, Scottish chemist William Ramsay stands out. He didn't just add one element, but an entire group to the periodic table: the noble gases. This achievement earned him a Nobel Prize in 1904.
Ramsay stumbled upon the noble gases in 1894 when he discovered argon. Argon is a colorless, odorless, and almost non-reactive gas. It's the most abundant noble gas on Earth, formed by the radioactive decay of potassium-40 in the Earth's crust and mantle.
Intriguingly, 1% of every breath we take is argon, yet it was only discovered in the late 19th century. Earlier, in 1785, British scientist Henry Cavendish noticed the first hints of its existence. Cavendish, while studying air composition, observed a small bubble of unknown gas remaining after removing all known gases from an air sample.
Over a century later, Ramsay and Lord Rayleigh tackled a similar question. Rayleigh found that nitrogen from the atmosphere had a higher density than nitrogen from chemical compounds. They suspected atmospheric nitrogen contained another gas. In 1894, they isolated this gas by repeatedly passing atmospheric nitrogen over hot magnesium, causing the nitrogen to bind and precipitate as magnesium nitride.
Ramsay and Rayleigh's publication in 1895 detailed their exhaustive attempts to make the new gas react with various substances. From oxygen and hydrogen to red-hot phosphorus and potassium nitrate, the gas remained unresponsive. They named it argon, from the Greek word 'argos' meaning inactive or lazy.
Shortly after, Ramsay discovered that helium also barely reacts with other substances. This led him to add a noble gas group to Mendeleev's periodic table. He soon expanded the group with neon, krypton, xenon, and later radon. For a while, some chemists believed these noble gases were completely unreactive.
However, in the 1960s, scientists managed to create some chemical compounds with noble gases. Argon held out longer. The first argon compound, argon fluorohydride, was only created in 2000, at -265°C and under UV radiation. Despite being chemically 'lazy,' argon has numerous applications.
Double-pane windows filled with argon provide better insulation due to its poor heat conductivity. It's also used to inflate diving suits. Old documents are protected from oxidation by storing them in non-reactive argon gas. Argon-filled incandescent lamps prevent filament burnout.
Like neon, argon emits bright light when an electric current passes through it. Pure argon glows purple, while with mercury, it glows blue. Blue-green argon lasers are used in ophthalmology and cancer therapy. The 'lazy' noble gas is put to work in many ways.