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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.

For non-A level students ...

(c) doc b KS4 Science GCSE/IGCSE/O Level Periodic Table notes links

 

INORGANIC Part 8 The p-block elements page sub-index: 8.1 Group 3/13 Introduction - Boron & Aluminium * 8.2 Group 4/14 Introduction - Carbon & Silicon - semi-metals e.g. Ge * 8.3 Group 5/15 Introduction - Nitrogen & Phosphorus * 8.4 Group 6/16 Introduction - Oxygen & Sulfur * 8.5 Group 0/18 The Noble Gases * 9. Group 7/17 The Halogens (separate section pages)

 

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 0/18 The Noble Gases

 

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
1

1H

2He

helium

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

neon

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

argon

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

krypton

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

xenon

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

radon

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

ununoctium

 

down group 0/18 ===>
property\Z symbol, name 2He helium 10Ne neon 18Ar argon 36Kr krypton 54Xe xenon 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 2.8.18.8 2.8.18.18.8 2.8.18.32.18.8
electron configuration 1s2 1s22s22p6 [Ne]3s23p6 [Ar]3d104s24p6 [Kr]4d105s25p6 [Xe]4f145d106s26p6
known oxidation states non stable non stable non stable an 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.

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
1

1H 1s1

2He

1s2

2 3Li [He]2s1 4Be [He]2s2 Electronic structure of selected elements of the periodic table

ZSymbol, Z = atomic/proton number = total electrons in neutral atom

elec. config. abbreviations: [He] = 1s2 [Ne] = 1s22s22p6

[Ar] = 1s22s22p63s23p6     [Kr] = 1s22s22p63s23p63d104s24p6

5B [He]2s22p1 6C [He]2s22p2 7N [He]2s22p3 8O [He]2s22p4 9F [He]2s22p5 10Ne

[He]2s22p6

3 11Na [Ne]3s1 12Mg [Ne]3s2 13Al [Ne]3s23p1 14Si [Ne]3s23p2 15P [Ne]3s23p3 16S [Ne]3s23p4 17Cl [Ne]3s23p5 18Ar

[Ne]3s23p6

4 19K [Ar]4s1 20Ca [Ar]4s2 21Sc [Ar] 3d14s2 22Ti [Ar] 3d24s2 23V [Ar] 3d34s2 24Cr [Ar] 3d54s1 25Mn [Ar] 3d54s2 26Fe [Ar] 3d64s2 27Co [Ar] 3d74s2 28Ni [Ar] 3d84s2 29Cu [Ar] 3d104s1 30Zn [Ar] 3d104s2 31Ga [Ar] 3d104s24p1 32Ge [Ar] 3d104s24p2 33As [Ar] 3d104s24p3 34Se [Ar] 3d104s24p4 35Br [Ar] 3d104s24p5 36Kr

[Ar] 3d104s24p6

5 37Rb [Kr]5s1 38Sr [Kr]5s2 39Y [Kr] 4d15s2 40Zr [Kr] 4d25s2 41Nb [Kr] 4d45s1 42Mo [Kr] 4d55s1 43Tc [Kr] 4d55s2 44Ru [Kr] 4d75s1 45Rh [Kr] 4d85s1 46Pd [Kr] 4d10 47Ag [Kr] 4d105s1 48Cd [Kr] 4d105s2 49In [Kr] 4d105s25p1 50Sn [Kr] 4d105s25p2 51Sb [Kr] 4d105s25p3 52Te [Kr] 4d105s25p4 53I [Kr] 4d105s25p5 54Xe

[Kr] 4d105s25p6

6 55Cs [Xe]6s1 56Ba [Xe]6s2 4f–block and 5d–block in period 6 including Lanthanide Series 81Tl [Xe] 4f145d106s26p1 82Pb [Xe] 4f145d106s26p2 83Bi [Xe] 4f145d106s26p3 84Po [Xe] 5d106s26p4 85At [Xe] 4f145d106s26p5 86Rn

[Xe] 4f145d106s26p6

7 87Fr [Rn]7s1 88Ra [Rn]7s2 5f–block & 6d–block including Actinide Series of Metals in period 7 113Uut [Rn] 5f146d107s27p1 114Fl [Rn] 5f146d107s27p2 115Uup [Rn] 5f146d107s27p3 116Lv [Rn] 5f146d107s27p4 117Uus [Rn] 5f146d107s27p5 118Uuo

[Rn] 5f146d107s27p6

  ***************************

 

  • GENERAL COMMENTS and TRENDS

  • 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
  • Advanced Inorganic Chemistry Page Index and LinksUSES of 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.
    • Advanced Inorganic Chemistry Page Index and LinksXENON 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.
  • 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.
    • 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.

Advanced Inorganic Chemistry Page Index and Links

WHAT NEXT?

INORGANIC Part 8 The p-block elements page sub-index: 8.1 Group 3/13 Introduction - Boron & Aluminium * 8.2 Group 4/14 Introduction - Carbon & Silicon - semi-metals e.g. Ge * 8.3 Group 5/15 Introduction - Nitrogen & Phosphorus * 8.4 Group 6/16 Introduction - Oxygen & Sulfur * 8.5 Group 0/18 The Noble Gases * 9. Group 7/17 The Halogens (separate section pages)

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

 

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