Argon

Photo Credit: Peroidic Table

Atomic Number: 18
Relative Atomic Mass: 39.9
Group: 18
Period: 3
Block: P

Symbol: Ar

Argon is a colourless, odourless gas which is innert to other substances. It makes up 0.94% of the Earth's atmosphere. Plus, Argon is the third most abundant atmospheric gas. Though levels have gradual increase since Earth was formed. That is due to Potassium-40, a higher atomic numbered element, turning into Argon as potassium decays.

Commercially, Argon is obtained by the distillation of liquid air.

The Discovery of Argon

Photo Credit: Nobel Prize

Argon was discovered, in the year 1894, by two chemist - Lord Rayleigh (British) and William Ramsay (Scottish). They seperated Argon from liquid air. Argon was only discovered because the two chemist were trying to explain why the density of Nitrogen difference from the decomposition of ammonia.
Ramsay removed all of the Nitrogen element from the gas. The chemisty did that by reacting the air with hot Magnesiums, making the compound Magnesium Nitride. Then the chemist examines the remaining gas through a spectum and saw two new groups of red and green lines. The confirmation of a brand new element.

Although, we have to not forget about Henry Cavendish (the discover of Hydrogen) who had the thought of 1% of air being unreactive, even at the most extreme environment. That 1% of air was Argon.  

Biological Uses

There is no known biological role for Argon.

It's Uses

• Argon is often used when an innert atmosphere is needed. 
• It is used in the production of titanium and other relative elements.
• It's used by Welders to protect the area.
• Argon is used in fluorescent lights and low-energy light bulbs. 
• Low-energy light bulbs often contain Mercury
• Double-glacing windows in between the panes.