Image by Greg Robson
Argon is a noble gas, which means it’s colourless, odourless and rarely reacts with anything around it. This doesn’t mean it’s boring though! Argon is the third most common gas in the Earth’s atmosphere as it makes up about 1% of the air around us, so it’s actually more common than carbon dioxide. It makes up a whopping 70% of the atmosphere of the planet Mercury.
Argon is used in fluorescent lights as it produces blue visible light, as well as ultraviolet light. Argon is used to make all of the blue eye-catching fluorescent signs and advertisements in Piccadilly Circus, London. Another noble gas, neon, is also used in these lights to produce an orangey red light.
Image by Sebastian Bertalan
Argon is still a gas even at temperatures far colder than in Antarctica, the coldest place on Earth at a mind-numbing –90°C. When argon is a liquid, between about –189°C and –185°C, it is used to destroy bad cancer cells in special operations called ‘cryosurgery’. Argon is also used in blue lasers in operations to destroy tumours, correct eye defects and mend broken arteries in the body.
Scientists suspected that there was another noble gas in the air as early as 1785, but it wasn’t properly discovered until over a 100 years later, in 1894. To find it, the scientists removed all the other gases from the air to see what was left! It was so important that in 1904 Lord Raleigh and Sir William Ramsay received the Nobel Prize in physics for their work.