Argon is a chemical element in the eighteen group of the periodic table. It is a noble gas, and it is the third most abundant gas in earth's atmosphere. Argon is the most common gas in the atmosphere besides Nitrogen and Oxygen. Argon is a noble gas (like helium) which means that it is completely inert.
Argon is often used when an inert atmosphere is needed. It is used in this way for the production of titanium and other reactive elements. It is also used by welders to protect the weld area and in incandescent light bulbs to stop oxygen from corroding the filament.
Argon has the atomic number 18 and is a noble gas found in group 18 in the Periodic Table. It is the third noble gas and sits below neon and above krypton. Argon is a colorless and odorless gas and does not react with other substances under normal conditions.
The nucleus consists of 18 protons (red) and 22 neutrons (orange). 18 electrons (white) occupy shells (rings); eight fill the outer (third) electron shell in what is a very stable configuration. The stability of an element's outer (valence) electrons determines its chemical and physical properties.
Although argon is abundant in the Earth’s atmosphere, it evaded discovery until 1894 when Lord Rayleigh and William Ramsay first separated it from liquid air. In fact the gas had been isolated in 1785 by Henry Cavendish who had noted that about 1% of air would not react even under the most extreme conditions. That 1% was argon.
Argon was discovered as a result of trying to explain why the
density of nitrogen extracted from air differed from that obtained
by the decomposition of ammonia.
Ramsay removed all the nitrogen from the gas he had extracted from
air, and did this by reacting it with hot magnesium, forming the
solid magnesium nitride. He was then left with a gas that would
not react and when he examined its spectrum he saw new groups of
red and green lines, confirming that it was a new element.
Argon provides an inert atmosphere in which welded metals will not oxidise. Argon is a colourless, odourless gas that is totally inert to other substances. Argon is often used when an inert atmosphere is needed. It is used in this way for the production of titanium and other reactive elements.
Argon makes up 0.94% of the Earth's atmosphere and is the third most abundant atmospheric gas. Levels have gradually increased since the Earth was formed because radioactive potassium-40 turns into argon as it decays. Argon is obtained commercially by the distillation of liquid air.
Argon is colorless, odorless, nonflammable and nontoxic as a solid, liquid or gas. Argon is chemically inert under most conditions and forms no confirmed stable compounds at room temperature. , and excited-state complexes, such as ArF, have been demonstrated.