The noble gases are a group of seven elements on the Periodic Table of Elements. Together they make up Group 18 on the table and include (in increasing atomic number) helium, neon, argon, krypton, xenon, radon and element 118, which has been temporarily named ununoctium. All noble gases display similar properties under standard conditions. They are colorless, tasteless, odorless and non-flammable.
It was previously thought that the noble gases were unable to form chemical bonds with the atoms of other elements. It's now known that this is possible, and they do form chemical compounds. The greater the atomic number of the element, the less abundant it is in the universe. Helium, with atomic number one, is the most abundant element of the noble gases and the most abundant element in general next to Hydrogen.The Earth's atmosphere contains all noble gases.
With the exception of helium and radon, noble gases are extracted from the air using a process called liquefaction of gas and fractional distillation. Helium is obtained from natural gas fields using cryogenic gas separation. Radon comes from the radioactive decay of radium compounds.
There are several industrial applications from the use of noble gases. Light bulbs and lamps are both manufactured with the help of noble gases. The elements also have medicinal applications. Helium is used to help asthmatics, while xenon aids in medical imaging.