State what are noble gases. Give a reason why noble gases have stable electronic configuration.

Noble gases have stable electronic configuration i.e., their valence shell is complete. They do not gain, lose or share electrons. Their atoms are extremely unreactive.

For an atom to achieve stable electronic configuration, it must have:

1. Two electrons in the first shell (outermost) like that of noble gas Helium. This is termed the Duplet Rule.
2. Eight electrons in the outermost shell like that of noble gases other than Helium. This is termed the Octet Rule.

The octet and duplet arrangement of elements represents stability and hence noble gases have stable electronic configuration.