What is group 18 elements or what is noble gases?

 

• The noble gases comprise of Helium, Neon, Argon, Krypton, Xenon and Radon.
• All these gases, except radon, are present in the atmosphere.
• Radon results from the disintegration of radium and is radioactive itself.
• These gases have highly stable s²p⁶ electronic configurations in their outer (valency) shells and, therefore, they have very little tendency to form chemical compounds with other elements.
• In fact, till comparatively recently, no chemical reaction of these elements was known and they were referred to as inert gases
• However, recent researches have shown that they do enter into chemical reactions with some specific elements under certain specific conditions forming chemical compounds.
• The word ‘inert’ therefore, is no longer considered appropriate.
• It is more usual now to refer to them as noble gases, the word ‘noble’ signifying that they enter into very few chemical reactions.
• Except helium, have the highly stable ns²p⁶ configurations in the outer (valency) shell.
• Helium has the stable s² configuration.