P - Block Elements

Elements and Compounds of Group-18

  • Zero group of periodic table includes gaseous elements, He, Ne, Ar, Kr, Xe and a radioactive element radon (Rn). These elements are characterised by ns2 np6 general electronic configuration.
  • On having very stable electronic configuration in their valency shell they are chemically inert and are known as inert gases (or) noble gases.
  • Argon is most abundant of all noble gases in the atmosphere.
  • CP/CV ratio of these gases is 1.67. This shows that all these gases are mono atomic in nature.
  • The different noble gases are absorbed by coconut charcoal at different temperatures. It provides a mean to separate these gases from one another.
  • The ease of liquefaction increases with increase in atomic number i.e from He to Rn because vander waal's attraction increases in same order.
  • Helium is used in helium thermometer for measuring extremely low temperatures.
  • Neon is used widely in preparing neon signals in many electronic appliances.

    Colour change and Neon glass tube
S.No Types of mixture Types of glass tube Colour of the light produced
1 Neon Colourless Orange red
2 Neon light red deep red
3 Neon-Argon Colourless ripple effect
4 Ne, Ar, Hg vapours Colourless Light blue
5 Ne, Ar, Hg vapours Purple dark blue
6 Ne, Ar, Hg vapours green Light green
  • Argon is mainly used in filling electrical lamps.
  • Krypton is used in filling luminous sign tubes and filament lamps.
  • Radon is used in the preparation of ointments for treatment of cancer.
  • The xenon fluorides are useful fluorinating agents.

    Stable compounds of Xe
Compound Oxidation state of Xe Hybridization No.of lone pair of electrons Shape
XeF2 +2 sp3d 3 Linear
XeF4 +4 sp3d2 2 Square Planar
XeF6 +6 sp3d3 1 Distorted pentagonal bipyramidal
XeOF2 +4 sp3d 2 T-shaped
XeOF4 +6 sp3d2 1 Square pyramidal
XeO3 6 sp3 1 Pyramidal


Part1: View the Topic in this Video from 0:07 to 6:56

Part2: View the Topic in this Video from 0:07 to 12:39

Part3: View the Topic in this Video from 0:07 to 10:29

Part4: View the Topic in this Video from 0:07 to 14:07

Part5: View the Topic in this Video from 0:07 to 10:21

Disclaimer: Compete.etutor.co may from time to time provide links to third party Internet sites under their respective fair use policy and it may from time to time provide materials from such third parties on this website. These third party sites and any third party materials are provided for viewers convenience and for non-commercial educational purpose only. Compete does not operate or control in any respect any information, products or services available on these third party sites. Compete.etutor.co makes no representations whatsoever concerning the content of these sites and the fact that compete.etutor.co has provided a link to such sites is NOT an endorsement, authorization, sponsorship, or affiliation by compete.etutor.co with respect to such sites, its services, the products displayed, its owners, or its providers.