Argon
Argon was the first noble gas to be discovered. The first hint of its existence came from English Scientist Henry Cavendish as far back as 1785. Cavendish was unhappy that so little was known about air, but was particularly unhappy about the lack of information know about the fraction of air which was not air. He knew nitrogen in air could be reacted with oxygen to form, ultimately, nitrous acid. He aimed to find out if all of that air that was not oxygen or carbon dioxide could be converted to nitrous acid. If it could, he would know that air was entirely oxygen, carbon dioxide and nitrogen. Cavendish then began to experiment by using an electric spark in air to react the oxygen and nitrogen to form nitrogen oxides, and then added additional oxygen until all the nitrogen had reacted. Cavendish used aqueous sodium hydroxide to remove the acidic nitrogen oxides from the apparatus; he then removed the remaining oxygen using potassium polysulfides. A small bubble of gas still remained after the experiment. Cavendish wrote that the bubble “was not more than one hundred and twentieth of the bulk of the phlosigated air [nitrogen].” Basically saying that the air is at least 99.3 percent nitrogen/ oxygen/ carbon dioxide with a maximum 0.7 percent of something else, something Cavendish was going to discover. 100 years after Cavendish’s experiment, scientists again began to think something about air didn’t quite add up. In 1892 English physicist John William Strutt (better known as Lord Rayleigh) announced that no matter how it was prepare, oxygen was always 15.882 times denser than hydrogen. His very precise work had taker ten years to complete. Lord Rayleigh’s paper about his experiment awakened the serious interest of Scottish chemist William Ramsay, who was already aware or the problem. In August 1884, Ramsay took air and removed its components oxygen, carbon dioxide, and nitrogen. He removed the nitrogen by reacting it with magnesium. After removing all the known gases from air, he found gas remaining that occupied one-eightieth of the original volume. Its spectrum matched no known gas. Rayleigh and Ramsay wrote a joint paper in 1895 notifying the world of their discovery. The new gad wouldn’t react with anything, so they named it argon, from the Greek “Argos” meaning inactive or lazy. Argon is found 0.93 percent in the atmosphere along with oxygen, nitrogen, and carbon dioxide. Argon is chemically inactive. On rare, occasions, and under extreme conditions, it forms weak compound like structures. Physically, argon is a colorless, odorless, and tasteless gas. Its density is said to be 1.784 grams per liter. Argon also changes from a gas to a liquid at -185.86oC (-302.55oF) and a liquid to a solid at -189.3oC (-308.8oF). Argon is used in electric light bulbs and in fluorescent tubes at a pressure of about 3