Editing Halogen (section)

{{short description|Group of chemical elements}}
{{About|the chemical series}}
{{Infobox periodic table group
| title       = Halogens
| group number= 17
| trivial name= halogens
| by element  = fluorine group
| CAS         = VIIA
| old IUPAC   = VIIB
| mark        = F,Cl,Br,I,At,Ts
| left        = [[Chalcogen|chalcogens]]
| right       = [[Noble gas|noble gases]]}}
{| class="floatright"
! colspan=2 style="text-align:left;" | ↓&nbsp;[[Period (periodic table)|Period]]
|-
! [[Period 2 element|2]]
| {{element cell image|9|Fluorine|F| |Gas|Halogen|Primordial|image=Liquid fluorine tighter crop.jpg|image caption=Liquid fluorine at cryogenic temperatures}}
|-
! [[Period 3 element|3]]
| {{element cell image|17|Chlorine|Cl| |Gas|Halogen|Primordial|image=Chlorine ampoule.jpg|image caption=Chlorine gas}}
|-
! [[Period 4 element|4]]
| {{element cell image|35|Bromine|Br| |Liquid|Halogen|Primordial|image=Bromine 25ml.jpg|image caption=Liquid bromine}}
|-
! [[Period 5 element|5]]
| {{element cell image|53|Iodine|I| |Solid|Halogen|Primordial|image=Iod kristall.jpg|image caption=Iodine crystal}}
|-
! [[Period 6 element|6]]
| {{element cell image|85|Astatine|At| |Solid|Halogen|From decay}}
|-
! [[Period 7 element|7]]
| {{element cell image|117|Tennessine|Ts| |Unknown phase|Halogen|Synthetic}}
|-
| colspan="2"|
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''Legend''
{| style="text-align:center; border:0;margin: 0 auto"
|-
| style="border: {{element color|Primordial}}; background:{{Element color|table mark}}; padding:0 2px;" |[[primordial element]]
|-
| style="border: {{element color|from decay}}; background:{{Element color|table mark}};" |[[Trace radioisotope|element from decay]]
|-
| style="border:{{element color|Synthetic}}; background:{{Element color|table mark}};" | [[Synthetic element|Synthetic]]
|}
|}

The '''halogens''' ({{IPAc-en|ˈ|h|æ|l|ə|dʒ|ə|n|,_|ˈ|h|eɪ|-|,_|-|l|oʊ|-|,_|-|ˌ|dʒ|ɛ|n}}<ref>{{cite book |last=Jones |first=Daniel |author-link=Daniel Jones (phonetician) |title=English Pronouncing Dictionary |editor=Peter Roach |editor2=James Hartmann |editor3=Jane Setter |place=Cambridge |publisher=Cambridge University Press |orig-year=1917 |year=2017 |isbn=978-3-12-539683-8 }}</ref><ref>{{MerriamWebsterDictionary|Halogen}}</ref><ref>{{Dictionary.com|Halogen}}</ref>) are a [[group (periodic table)|group]] in the [[periodic table]] consisting of six chemically related [[chemical element|elements]]: [[fluorine]] (F), [[chlorine]] (Cl), [[bromine]] (Br), [[iodine]] (I), and the [[radioactive]] elements [[astatine]] (At) and [[tennessine]] (Ts), though some authors<ref>[https://www.researchgate.net/profile/Burkhard-Fricke Fricke, Burkhard] [2007.12.??] [https://www.researchgate.net/publication/225672062_Superheavy_elements_a_prediction_of_their_chemical_and_physical_properties Superheavy elements a prediction of their chemical and physical properties] PDF | "Element 117" | www.researchgate.net | Retrieved - 2023.08.13 (20:58:??) -- yyyy.mm.dd (hh:mm:ss)</ref> would exclude tennessine as its chemistry is unknown and is theoretically expected to be more like that of [[gallium]]. In the modern [[IUPAC]] nomenclature, this group is known as '''group 17'''.<ref>{{Cite book |title=Nomenclature of inorganic chemistry: IUPAC Recommendations 2005 |date=2005 |publisher=Royal Society of Chemistry |isbn=978-0-85404-438-2 |editor-last=Union internationale de chimie pure et appliquée |location=Cambridge |pages=51}}</ref>

The word "halogen" means "salt former" or "salt maker". When halogens react with [[metal]]s, they produce a wide range of [[Salt (chemistry)|salts]], including [[calcium fluoride]], [[sodium chloride]] (common table salt), [[silver bromide]] and [[potassium iodide]].<ref>{{Cite web |title=Chemical properties of the halogens - Group 17 - the halogens - Edexcel - GCSE Combined Science Revision - Edexcel |url=https://www.bbc.co.uk/bitesize/guides/ztjy6yc/revision/2 |access-date=2022-03-21 |website=BBC Bitesize |language=en-GB}}</ref>

The group of halogens is the only [[Group (periodic table)|periodic table group]] that contains elements in three of the main [[State of matter|states of matter]] at [[standard temperature and pressure]], though not far above room temperature the same becomes true of groups [[alkali metals|1]] and [[pnictogen|15]], assuming white phosphorus is taken as the standard state.<ref group="n">This could also be the case for [[Group 12 element|group 12]], although [[copernicium]]'s melting and boiling points are still uncertain.</ref> All of the halogens form acids when bonded to hydrogen. Most halogens are typically produced from [[mineral]]s or [[salt (chemistry)|salts]]. The middle halogens—chlorine, bromine, and iodine—are often used as [[disinfectant]]s. Organobromides are the most important class of [[flame retardant]]s, while elemental halogens are dangerous and can be toxic.
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