p block elements notes: Group 0/18 Noble Gases: Advanced  Level Inorganic Chemistry

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Doc Brown's Chemistry  - Advanced Level Inorganic Chemistry Periodic Table Revision Notes

Part 8. The p-block elements: 8.5 Group 0/18 The Noble Gases

The physical and chemical properties of the noble gases are described and explained and noble gas group trends.

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Sub-index for this page on group 0/18 noble gas elements

(1) The Noble Gases - their position in the periodic table, data and electron configurations

(2) Some general comments and trends for group 0/18 noble gas elements of the periodic table

(3) Uses of the group 0/18 Noble Gases

(4) Compounds of the noble gases, particularly xenon

(1) Group 0/18 The Noble Gases - their position in the periodic table, data and electron configurations

Pd s block d blocks and f blocks of metallic elements p block elements
Gp1 Gp2 Gp3/13 Gp4/14 Gp5/15 Gp6/16 Gp7/17 Group 0/18




2 3Li 4Be The modern Periodic Table of Elements

ZSymbol, z = atomic or proton number

highlighting position of Group 0/Group 18 Noble Gases

5B 6C 7N 8O 9F 10Ne


3 11Na 12Mg 13Al 14Si 15P 16S 17Cl 18Ar


4 19K 20Ca 21Sc 22Ti 23V 24Cr 25Mn 26Fe 27Co 28Ni 29Cu 30Zn 31Ga 32Ge 33As 34Se 35Br 36Kr


5 37Rb 38Sr 39Y 40Zr 41Nb 42Mo 43Tc 44Ru 45Rh 46Pd 47Ag 48Cd 49In 50Sn 51Sb 52Te 53I 54Xe


6 55Cs 56Ba 57-71 72Hf 73Ta 74W 75Re 76Os 77Ir 78Pt 79Au 80Hg 81Tl 82Pb 83Bi 84Po 85At 86Rn


7 87Fr 88Ra 89-103 104Rf 105Db 106Sg 107Bh 108Hs 109Mt 110Ds 111Rg 112Cn 113Nh 114Fl 115Mc 116Lv 117Ts 118Og



Data down the Noble Gas Group 0/18 ===>
property\Z symbol, name 2He










86Rn radon (radioactive)
Period 1 2 3 4 5 6
melting point/oC -270 -249 -189 -157 -112 -71
boiling point/oC -269 -246 -186 -152 -108 -62
density/gcm-3(liquid) 0.12 1.21 1.40 2.16 3.50 na
1st IE/kJmol-1 2370 2080 1520 1350 1170 1040
electron configuration 2 2.8 2.8.8
electron configuration 1s2 1s22s22p6 [Ne]3s23p6 [Ar]3d104s24p6 [Kr]4d105s25p6 [Xe]4f145d106s26p6
known oxidation states non stable non stable non stable very unstable +2 +2,4,6,8 na
electronegativity (i) 5.50 4.84 3.20 2.94 2.40 2.0
atomic covalent radius/pm (ii) He   49 Ne   51 Ar   94 Kr   109 Xe  130 Rn   136

Note (i) Theoretical estimates of Pauling electronegativities (some uncertainty in values)

(ii) He to Ar, Kr?, theoretical calculations of atomic radius.

(iii) na = not applicable

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(2) Some general comments and trends for group 0/18 noble gas elements of the periodic table

  • The p-block Group of Noble Gases are the last group in the Periodic Table i.e. they form the last elements at the end of a period and are all non-metals.

  • They are all non-metallic elements and all are colourless gases at room temperature and pressure with very low melting points and boiling points.

  • They form 1% of air, and most of this is argon. All the noble gases, except radon, are separated by the fractional distillation of liquified air.

  • % in air by volume: 0.0005% He, 0.0018% Ne, 0.93% Ar, 0.0001% Kr, 0.00001% Xe, ?% Rn - impossible to be zero, but an extremely minute trace hopefully! (varies with local geology)
  • Helium can also be obtained from natural gas wells where it has accumulated from radioactive decay (alpha particles become atoms of helium gas when they gain two electrons).

  • They are very unreactive elements because the highest occupied electron level shell is completely full, meaning they have a full shell of outer electrons! They have no 'wish' electronically to share electrons to form a covalent bond or to lose or gain electrons to form an ionic bond. In other words, they are electronically very stable.

  • They exist as single atoms, that is they are monatomic He Ne Ar etc. (NOT diatomic molecules as with many other gases - reasons given above). This is because of their electronic stability.

  • Their very inertness is an important feature of their practical uses. 

  • Down the Group with increasing atomic number ...

    • The melting point and boiling point steadily increase as the number of electrons in the atoms increases so does the 'intermolecular forces' - increase in instantaneous dipole - induced dipole forces still exist, even between individual atoms.

    • The density steadily increases.

    • They are more likely to react and form a compound with very reactive elements like fluorine.

  • Stable compounds of xenon are now known and synthesised BUT not before 1961!

  • The first 3 Noble Gases, showing their electron arrangements (in various styles) with full very stable outer shells.
  • Helium, with one full shell only (outer = inner !) has the highest ionisation energy of any element and is chemically the most stable and least reactive of any element in the periodic table and has no meaningful chemistry.
  • Noble Gases1s2 Noble Gases1s22s22p6 Noble Gases[Ne]3s23p6

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(3) Uses of the group 0/18 Noble Gases

  • Noble GasesHELIUM gas is much less dense than air (lighter) and is used in balloons and 'airships'. Because of its inertness it doesn't burn in air UNLIKE hydrogen which used to be used in large balloons with  'flammable' consequences e.g. like the R101 airship disaster! Helium is also used in gas mixtures for deep-sea divers.
  • Noble Gases NEON gives out light when high voltage electricity is passed through it, so its used in glowing 'neon' advertising signs and fluorescent lights. 
  • Noble GasesNoble Gases ARGON, like all the Noble Gases, is chemically inert. It used in filament bulbs because the metal filament will not burn in Argon and it reduces evaporation of the metal filament. It is also used to produce an inert atmosphere in high temperature metallurgical processes, eg in welding where it reduces brittle oxide formation reducing the weld quality. Its bubbles are used to stir mixtures in steel production. Argon is the cheapest to produce.
  • KRYPTON Not used by superman! BUT is used in fluorescent bulbs, flash bulbs and laser beams.
  • XENON used in fluorescent bulbs, flash bulbs and lasers.
  • Noble GasesRADON Rocks, e.g. granite, can contain uranium metal compounds which are radioactive. When they 'decay' radioactively, radioactive and harmful radon gas can be formed. Radon has almost no uses, but does have dangers! Radio-isotopes of radon are produced by radioactive decay of heavy metals (e.g. uranium) in the ground. Can build up in cellars. Like all radio-isotopes it can cause cell damage (DNA) and ultimately cancer (see link below). However it is used in some forms of cancer treatment.

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(4) NOBLE GAS COMPOUNDS - yes they do exist!

  • It was long recognised that noble gases had particularly stable electron configurations and were not expected to ever form stable chemical compounds.
  • The highest s and p levels are full, as with all Group 0 noble gases and these electrons are most reluctant to engage in sharing electrons to form a covalent bond, and even less so, to form a positive ion.
  • However an English chemist, Neil Bartlett, working in Canada in 1962, found that platinum hexafluoride (PtF6), a very reactive compound itself, actually reacted with xenon to form a complex (XePtF6), the very first noble gas compound ever!, and this was the start of the new branch of chemistry!
  • So, from the early 1960's many noble gas compounds have been made, but only xenon compounds are stable and usually combined with oxygen and fluorine, which, not surprisingly, are the more reactive non-metals e.g.
  • Xe(g) + 2F2(g) ====> XeF4(g) (using Ni catalyst 60oC)
    • The molecule has a square planar shape.
  • There is now quite an extensive chemistry of xenon e.g.
    • xenon(II) fluoride XeF2 (linear), xenon(VI) fluoride XeF6
    • xenon(VI) oxide (xenon trioxide) XeO3 which has a trigonal pyramid shape
    • xenon oxytetrafluoride XeOF4 (Xe oxidation state +6)
    • the xenonate(VIII) ion XeO64- ion exists in salts such as Na4XeO6.8H2O which is stable and can be crystallised as a hydrated salt from aqueous solution.
      • This exhibits the maximum oxidation state theoretically expected for a noble gas below helium - 8 outer electrons that can be involved in covalent chemical bonding.
  • I don't know of any stable compound of helium and argon, but argon(II) fluoride ArF2 has been prepared at low temperatures (<40K, <-233oC), via uv light shone onto frozen argon in the presence of fluorine?).
  • Very unstable krypton(II) fluoride KrF2 and krypton(IV) fluoride KrF4 have been prepared, but despite the great reluctance of krypton to react - but we are dealing with fluorine, the most reactive element known and one of the most powerful oxidising agents known.

PLEASE NOTE GCSE Level periodic table notes are on separate webpages

INORGANIC Parts 8 and 9 p-block element sub–index: 8.1 Group 3/13 Introduction – emphasis on boron and aluminium * 8.2 Group 4/14 Introduction – emphasis on carbon and silicon – semi–metals e.g. Ge * 8.3 Group 5/15 Introduction – emphasis on nitrogen and phosphorus * 8.4 Group 6/16 Introduction – emphasis on oxygen and sulfur * 8.5 Group 0/18 The Noble Gases * 9. Group 7/17 The Halogens

Advanced Level Inorganic Chemistry Periodic Table Index: Part 1 Periodic Table history Part 2 Electron configurations, spectroscopy, hydrogen spectrum, ionisation energies * Part 3 Period 1 survey H to He * Part 4 Period 2 survey Li to Ne * Part 5 Period 3 survey Na to Ar * Part 6 Period 4 survey K to Kr and important trends down a group * Part 7 s–block Groups 1/2 Alkali Metals/Alkaline Earth Metals * Part 8  p–block Groups 3/13 to 0/18 * Part 9 Group 7/17 The Halogens * Part 10 3d block elements & Transition Metal Series * Part 11 Group & Series data & periodicity plots

Group numbering and the modern periodic table

The original group numbers of the periodic table ran from group 1 alkali metals to group 0 noble gases. To account for the d block elements and their 'vertical' similarities, in the modern periodic table, groups 3 to group 0 are numbered 13 to 18. So, the p block elements are referred to as groups 13 to group 18 at a higher academic level, though the group 3 to 0 notation is usually assigned at a lower academic level.

Periodic Table - Doc Brown's Chemistry  Revising Advanced Level Inorganic Chemistry Periodic Table Revision Notes. Website content © Dr Phil Brown 2000+. All copyrights reserved on Doc Brown's chemistry revision notes, images, quizzes, worksheets etc. Copying of Doc Brown's website material is NOT permitted. Advanced level revision notes on the p-block metals and non-metals

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