Editing Halogen (section)

=== Physical and atomic ===
The table below is a summary of the key physical and atomic properties of the halogens. Data marked with question marks are either uncertain or are estimations partially based on [[periodic trends]] rather than observations.

{| class="wikitable" style="text-align:center"
!Halogen
!Standard [[atomic weight]]<br>([[unified atomic mass unit|u]]){{refn|The number given in [[bracket|parentheses]] refers to the [[Uncertainty#In measurements|measurement uncertainty]]. This uncertainty applies to the [[significant figure|least significant figure]](s) of the number prior to the parenthesized value (i.e., counting from rightmost digit to left). For instance, {{val|1.00794|(7)}} stands for {{val|1.00794|0.00007}}, while {{val|1.00794|(72)}} stands for {{val|1.00794|0.00072}}.<ref>{{cite web|url=http://physics.nist.gov/cgi-bin/cuu/Info/Constants/definitions.html|title=Standard Uncertainty and Relative Standard Uncertainty|website=[[CODATA]] reference|publisher=[[National Institute of Standards and Technology]]|access-date=26 September 2011}}</ref>|group=n}}<ref name="atomicweights2009">{{cite journal|last1=Wieser |first1=Michael E.|last2=Coplen|first2=Tyler B. |year=2011|title=Atomic weights of the elements 2009 (IUPAC Technical Report)|journal=[[Pure and Applied Chemistry|Pure Appl. Chem.]] |volume=83|issue=2|pages=359–396|doi=10.1351/PAC-REP-10-09-14|s2cid=95898322|url=http://iupac.org/publications/pac/pdf/2011/pdf/8302x0359.pdf|access-date=5 December 2012 }}</ref>
![[Melting point]]<br>([[kelvin|K]])
![[Melting point]]<br>([[Celsius|°C]])
![[Boiling point]]<br>([[kelvin|K]])<ref name="RubberBible84th">{{cite book | editor = Lide, D. R. | title = CRC Handbook of Chemistry and Physics | edition = 84th | location = Boca Raton, FL |publisher = CRC Press | year = 2003 }}</ref>
![[Boiling point]]<br>([[Celsius|°C]])<ref name="RubberBible84th"/>
![[Density]]<br>(g/cm<sup>3</sup>at 25&nbsp;°C)
![[Electronegativity]]<br>([[Pauling scale|Pauling]])
!First [[ionization energy]]<br>([[Kilojoule per mole|kJ·mol<sup>−1</sup>]]) !! [[Covalent radius]]<br>([[picometre|pm]])<ref name="slater64">{{cite journal|last=Slater|first=J. C.|year=1964|title=Atomic Radii in Crystals|journal=[[Journal of Chemical Physics]]|volume=41|issue=10|pages=3199–3205|bibcode=1964JChPh..41.3199S|doi=10.1063/1.1725697}}</ref>
|-
| [[Fluorine]] || 18.9984032(5) || 53.53 || −219.62 || 85.03 || −188.12 || 0.0017 || 3.98 || 1681.0 || 71
|-
| [[Chlorine]] || [35.446; 35.457]{{refn|The average atomic weight of this element changes depending on the source of the chlorine, and the values in brackets are the upper and lower bounds.<ref name="atomicweights2009"/>|group=n}} || 171.6 || −101.5 || 239.11 || −34.04 || 0.0032 || 3.16 || 1251.2 || 99
|-
| [[Bromine]] || 79.904(1) || 265.8 || −7.3 || 332.0 || 58.8 || 3.1028 || 2.96 || 1139.9 || 114
|-
| [[Iodine]] || 126.90447(3) || 386.85 || 113.7 || 457.4 || 184.3 || 4.933 || 2.66 || 1008.4 || 133
|-
| [[Astatine]] || [210]{{refn|name=unstable|The element does not have any stable [[nuclide]]s, and the value in brackets indicates the [[mass number]] of the longest-lived [[isotope]] of the element.<ref name="atomicweights2009"/>|group=n}} || 575 || 302 || ? 610 || ? 337 || ? 6.2–6.5<ref name=Bonchev>{{cite journal |last1=Bonchev |first1=Danail |last2=Kamenska |first2=Verginia |year=1981 |title=Predicting the properties of the 113–120 transactinide elements |journal=The Journal of Physical Chemistry |volume=85 |issue=9 |pages=1177–86 |doi=10.1021/j150609a021 }}</ref> || 2.2 || 899.0<ref name=1IP>{{cite journal |last1=Rothe |first1=S. |last2=Andreyev |first2=A. N. |last3=Antalic |first3=S. |last4=Borschevsky |first4=A. |last5=Capponi |first5=L. |last6=Cocolios |first6=T. E. |last7=De Witte |first7=H. |last8=Eliav |first8=E. |last9=Fedorov |first9=D. V. | display-authors=8
|year=2013 |title=Measurement of the First Ionization Potential of Astatine by Laser Ionization Spectroscopy |journal=Nature Communications |volume=4 |doi=10.1038/ncomms2819 |url=https://www.researchgate.net/publication/236836716 |last10=Fedosseev |first10=V. N. |last11=Fink |first11=D. A. |last12=Fritzsche |first12=S. |last13=Ghys |first13=L. |last14=Huyse |first14=M. |last15=Imai |first15=N. |last16=Kaldor |first16=U. |last17=Kudryavtsev |first17=Yuri |last18=Köster |first18=U. |last19=Lane |first19=J. F. W. |last20=Lassen |first20=J. |last21=Liberati |first21=V. |last22=Lynch |first22=K. M. |last23=Marsh |first23=B. A. |last24=Nishio |first24=K. |last25=Pauwels |first25=D. |last26=Pershina |first26=V. |last27=Popescu |first27=L. |last28=Procter |first28=T. J. |last29=Radulov |first29=D. |last30=Raeder |first30=S. |pages=1–6 |pmid=23673620 |pmc=3674244|bibcode=2013NatCo...4.1835R }}</ref> || ? 145<ref>{{Cite web|url=https://www.thoughtco.com/astatine-facts-element-ar-606501|title=Get Facts About the Element Astatine|website=www.thoughtco.com|accessdate=November 12, 2021}}</ref>
|-
| [[Tennessine]] || [294]{{refn|name=unstable|group=n}} || ? 623-823<ref name="thoughtco.com">{{Cite web|url=https://www.thoughtco.com/element-117-facts-ununseptium-or-uus-3880071|title=How Much Do You Know About the Element Tennessine?|website=www.thoughtco.com|accessdate=November 12, 2021}}</ref> || ? 350-550<ref name="thoughtco.com"/> || ? 883<ref name="thoughtco.com"/> || ? 610<ref name="thoughtco.com"/> || ? 7.1-7.3<ref name="thoughtco.com"/> || - || ? 743<ref>{{Cite web|url=https://www.webelements.com/tennessine/atoms.html|title=WebElements Periodic Table » Tennessine » properties of free atoms|website=www.webelements.com|accessdate=November 12, 2021}}</ref> || ? 157<ref name="thoughtco.com"/>
|}

{| class="wikitable" style="white-space:nowrap;"
|-
!''[[Atomic number|Z]]'' !! [[Chemical element|Element]] !! Electrons per [[Electron shell|shell]]

|-
| 9 || fluorine || 2, 7
|-
| 17 || chlorine|| 2, 8, 7
|-
| 35 || bromine || 2, 8, 18, 7
|-
| 53 || iodine || 2, 8, 18, 18, 7
|-
| 85 || astatine || 2, 8, 18, 32, 18, 7
|-
| 117 || tennessine || 2, 8, 18, 32, 32, 18, 7 ''(predicted)''<ref name=Haire>{{Cite book |publisher= [[Springer Science+Business Media]] |location=Dordrecht, The Netherlands |bibcode=2011tcot.book.....M |doi =10.1007/978-94-007-0211-0 |editor1-last=Morss |editor1-first=Lester R |editor2-last=Edelstein |editor2-first=Norman M |editor3-last=Fuger| editor3-first=Jean |isbn =978-94-007-0210-3 |last1= Morss |first1= Lester R. |last2= Edelstein |first2= Norman M. |last3= Fuger |first3= Jean |year = 2011 |title = The Chemistry of the Actinide and Transactinide Elements }}</ref>
|}
[[File:Pressure halogens.png|thumb|366x366px|Boiling or sublimation temperature dependence for halogens at various pressures. The vertical bar indicates the melting point]]
{| class="wikitable"
|+Sublimation or boiling point (<sup>o</sup>C) of halogens at various pressures<ref>{{Cite web |title=Краткий справочник физико-химических величин Равделя, Л.: Химия, 1974 г. – 200 стр. \\ стр 67 табл. 24. |url=https://rushim.ru/books/spravochniki/mishenko.pdf}}</ref>
| colspan="2" rowspan="1" |Tmelt (<sup>о</sup>С)
| −100.7
| −7.3
|112.9
|-
!log(P[Pa])
!mmHg
!Cl<sub>2</sub>
!Br<sub>2</sub>
!I<sub>2</sub>
|-
|2.12490302
|1
| −118
| −48.7
|38.7
|-
|2.82387302
|5
| −106.7
| −32.8
|62.2
|-
|3.12490302
|10
| −101.6
| −25
|73.2
|-
|3.42593302
|20
| −93.3
| −16.8
|84.7
|-
|3.72696301
|40
| −84.5
| −8
|97.5
|-
|3.90305427
|60
| −79
| −0.6
|105.4
|-
|4.12490302
|100
| −71.7
|9.3
|116.5
|-
|4.42593302
|200
| −60.2
|24.3
|137.3
|-
|4.72696301
|400
| −47.3
|41
|159.8
|-
|5.00571661
|760
| −33.8
|58.2
|183
|-
!log(P[Pa])
!atm
!Cl<sub>2</sub>
!Br<sub>2</sub>
!I<sub>2</sub>
|-
|5.00571661
|1
| −33.8
|58.2
|183
|-
|5.30674661
|2
| −16.9
|78.8
|
|-
|5.70468662
|5
|10.3
|110.3
|
|-
|6.00571661
|10
|35.6
|139.8
|
|-
|6.30674661
|20
|65
|174
|
|-
|6.48283787
|30
|84.8
|197
|
|-
|6.6077766
|40
|101.6
|215
|
|-
|6.70468662
|50
|115.2
|230
|
|-
|6.78386786
|60
|127.1
|243.5
|
|}

==== Isotopes ====
Fluorine has one stable and naturally occurring [[isotopes of fluorine|isotope]], fluorine-19. However, there are trace amounts in nature of the radioactive isotope fluorine-23, which occurs via [[cluster decay]] of [[protactinium-231]]. A total of eighteen isotopes of fluorine have been discovered, with atomic masses ranging from 13 to 31. 

Chlorine has two stable and naturally occurring [[isotopes of chlorine|isotopes]], chlorine-35 and chlorine-37. However, there are trace amounts in nature of the isotope [[chlorine-36]], which occurs via [[spallation]] of argon-36. A total of 24 isotopes of chlorine have been discovered, with atomic masses ranging from 28 to 51.<ref name = "Nature's Building Blocks"/>

There are two stable and naturally occurring [[isotopes of bromine]], bromine-79 and bromine-81. A total of 33 isotopes of bromine have been discovered, with atomic masses ranging from 66 to 98. 

There is one stable and naturally occurring [[isotopes of iodine|isotope of iodine]], [[iodine-127]]. However, there are trace amounts in nature of the radioactive isotope [[iodine-129]], which occurs via spallation and from the radioactive decay of uranium in ores. Several other radioactive isotopes of iodine have also been created naturally via the decay of uranium. A total of 38 isotopes of iodine have been discovered, with atomic masses ranging from 108 to 145.<ref name = "Nature's Building Blocks"/>

There are no stable [[isotopes of astatine]]. However, there are four naturally occurring radioactive isotopes of astatine produced via radioactive decay of [[uranium]], [[neptunium]], and [[plutonium]]. These isotopes are astatine-215, astatine-217, astatine-218, and astatine-219. A total of 31 isotopes of astatine have been discovered, with atomic masses ranging from 191 to 227.<ref name = "Nature's Building Blocks"/>

There are no stable [[isotopes of tennessine]]. Tennessine has only two known [[synthetic radioisotope]]s, tennessine-293 and tennessine-294.