Editing Nonmetal (section)

==Comparison of selected properties==
The two tables in this section list some of the properties of five types of elements (noble gases, halogen nonmetals, unclassified nonmetals, metalloids and, for comparison, metals) based on their most stable forms at standard temperature and pressure. The dashed lines around the columns for metalloids signify that the treatment of these elements as a distinct type can vary depending on the author, or classification scheme in use.

=== Physical properties by element type ===
{{hatnote|See also {{slink||Physical}} }}

[[Physical property|Physical properties]] are listed in loose order of ease of their determination.

{|class="wikitable" style="font-size:95%"
|-
!rowspan="2" style="horizontal=align:center; font-size:105%""|Property
!colspan="5" style="horizontal=align:center; font-size:105%""|Element type
|-
! scope="col" style="width:17%; text-align:left"|Metals
! scope="col" style="width:17%; border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD; border-top:2px dashed #CDCDCD; text-align:left"|Metalloids
! scope="col" style="width:17%; text-align:left|Unc. nonmetals
! scope="col" style="width:17%; text-align:left"|Halogen nonmetals
! scope="col" style="width:17%; text-align:left"|Noble gases
|- style="vertical-align:top"
| scope="row" |General physical appearance
| lustrous<ref name="Kneen"/>
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD|lustrous<ref name="Rochow 1966, p. 4">[[#Rochow1966|Rochow 1966, p. 4]]</ref>
| {{indented plainlist|indent=0.9em|
* ◇ lustrous: carbon, phosphorus, selenium<ref>[[#Wiberg|Wiberg 2001, p. 780]]; [[#Emsley2011|Emsley 2011, p. 397]]; [[#Rochow1966|Rochow 1966, pp. 23, 84]]</ref>
* ◇ colored: sulfur<ref>[[#Kneen|Kneen, Rogers & Simpson 1972, p. 439]]</ref>
* ◇ colorless: hydrogen, nitrogen, oxygen<ref>[[#Kneen|Kneen, Rogers & Simpson 1972, pp. 321, 404, 436]]</ref>}}
| {{indented plainlist|indent=0.9em|
* ◇ lustrous: iodine<ref name="Vernon2013"/>
* ◇ colored: fluorine, chlorine, bromine<ref>[[#Kneen|Kneen, Rogers & Simpson 1972, p. 465]]</ref>}}
| colorless<ref>[[#Kneen|Kneen, Rogers & Simpson 1972, p. 308]]</ref>
|- style="vertical-align:top"
| scope="row" rowspan=3|Form and density<ref>[[#Tregarthen|Tregarthen 2003, p. 10]]</ref>
| solid <br>(Hg liquid)
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD| solid
| solid or gas
| solid or gas <br>(bromine liquid)
| gas
|- style="vertical-align:top"
|often [[Heavy metals|high density]] such as iron, lead, tungsten
|style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD|low to moderately high density
|low density
|rowspan=2| low density
|low density
|- style="vertical-align:top"
|some [[light metals]] including beryllium, magnesium, aluminium
|style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD|all lighter than iron
|hydrogen, nitrogen lighter than air<ref>[[#Lewis|Lewis 1993, pp. 28, 827]]</ref>
|helium, neon lighter than air<ref>[[#Lewis|Lewis 1993, pp. 28, 813]]</ref>
|- style="vertical-align:top"
| scope="row" | [[Plasticity (physics)|Plasticity]]
| mostly malleable and ductile<ref name="Kneen"/>
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD|often brittle<ref name="Rochow 1966, p. 4" />
| phosphorus, sulfur, selenium, brittle{{efn|All four have less stable non-brittle forms: carbon as [[Graphite#Expanded graphite|exfoliated (expanded) graphite]],<ref name="Chung">[[#Chung|Chung 1987]]</ref><ref>[[#Godfrin|Godfrin & Lauter 1995, pp. 216‒218]]</ref> and as [[carbon nanotube]] wire;<ref name="Janas">[[#Janas|Janas, Cabrero-Vilatela & Bulmer 2013]]</ref> phosphorus as white phosphorus (soft as wax, pliable and can be cut with a knife, at room temperature);<ref name="Holderness 1979, p. 255" /> sulfur as plastic sulfur;<ref name="ReferenceE" /> and selenium as selenium wires.<ref name="ReferenceF" />}}
| iodine brittle<ref>[[#Wiberg|Wiberg 2001, p. 416]]</ref>
| not applicable
|- style="vertical-align:top"
| scope="row" |[[Electrical resistivity and conductivity|Electrical conductivity]]
| good{{efn|Metals have electrical conductivity values of from {{val|6.9|e=3|u=S•cm<sup>−1</sup>}} for [[manganese]] to {{val|6.3|e=5}} for [[silver]].<ref>[[#Desai|Desai, James & Ho 1984, p. 1160]]; [[#Matula|Matula 1979, p. 1260]]</ref>}}
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD|{{indented plainlist|indent=0.9em|
* ◇ moderate: boron, silicon, germanium, tellurium
* ◇ good: arsenic, antimony{{efn|Metalloids have electrical conductivity values of from {{val|1.5|e=-6|u=S•cm<sup>−1</sup>}} for boron to {{val|3.9|e=4}} for [[arsenic]].<ref>[[#Schaefer|Schaefer 1968, p. 76]]; [[#Carapella|Carapella 1968, pp. 29‒32]]</ref>}}
  }}
| {{indented plainlist|indent=0.9em|
* ◇ poor: hydrogen, nitrogen, oxygen, sulfur
* ◇ moderate: phosphorus, selenium
* ◇ good: carbon{{efn|Unclassified nonmetals have electrical conductivity values of from ca. {{val|1|e=−18|u=S•cm<sup>−1</sup>}} for the elemental gases to {{val|3|e=4}} in graphite.<ref name="Bog">[[#Bogoroditskii1967|Bogoroditskii & Pasynkov 1967, p. 77]]; [[#Jenkins|Jenkins & Kawamura 1976, p. 88]]</ref>}}
  }}
| {{indented plainlist|indent=0.9em|
* ◇ poor: fluorine, chlorine, bromine
* ◇ moderate: I{{efn|Halogen nonmetals have electrical conductivity values of from ca. {{val|1|e=-18|u=S•cm<sup>−1</sup>}} for {{abbr|F|fluorine}} and {{abbr|Cl|chlorine}} to {{val|1.7|e=-8|u=S•cm<sup>−1</sup>}} for iodine.<ref name="Bog"/><ref name="Greenwood 2002, p. 804">[[#Greenwood|Greenwood & Earnshaw 2002, p. 804]]</ref>}}
  }}
| poor{{efn|Elemental gases have electrical conductivity values of ca. {{val|1|e=−18|u=S•cm<sup>−1</sup>}}.<ref name="Bog"/>}}
|- style="vertical-align:top"
| scope="row" |[[Electronic band structure|Electronic structure]]<ref name="K&W">[[#Keeler|Keeler & Wothers 2013, p. 293]]</ref>
| metal (beryllium, strontium, α-tin, ytterbium, bismuth are semimetals)
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD; border-bottom:2px dashed #CDCDCD"| semimetal (arsenic, antimony) or semiconductor
| {{indented plainlist|indent=0.9em|
* ◇ semimetal: carbon
* ◇ semiconductor: phosphorus
* ◇ insulator: hydrogen, nitrogen, oxygen, sulfur
  }}
| semiconductor ({{abbr|I|iodine}}) or insulator
| insulator
|}

=== Chemical properties by element type ===
{{hatnote|See also {{slink||Chemical}}}}

[[Chemical properties]] are listed from general characteristics to more specific details.

{|class="wikitable" style="font-size:95%"
|-
!rowspan="2" style="horizontal=align:center; font-size:105%""|Property
!colspan="5" style="horizontal=align:center; font-size:105%""|Element type
|-
! scope="col" style="width:17%; text-align:left"|Metals
! scope="col" style="width:17%; text-align:left; border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD; border-top:2px dashed #CDCDCD"|Metalloids
! scope="col" style="width:17%; text-align:left" | Unc. nonmetals
! scope="col" style="width:17%; text-align:left"|Halogen nonmetals
! scope="col" style="width:17%; text-align:left"|Noble gases
|- style="vertical-align:top"
| scope="row" |General chemical behavior
| {{indented plainlist|indent=0.9em|
* ◇ strong to weakly metallic<ref>[[#Kneen|Kneen, Rogers & Simpson 1972, p. 264]]</ref>
* ◇ [[noble metal]]s are relatively inert<ref>[[#Rayner|Rayner-Canham 2018, p. 203]]</ref>
  }}
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD|weakly nonmetallic{{efn|Metalloids always give "compounds less acidic in character than the corresponding compounds of the [typical] nonmetals."<ref name="Rochow 1966, p. 4" />}}
| moderately nonmetallic<ref name="W2009">[[#Welcher|Welcher 2009, p. 3–32]]: "The elements change from{{nbsp}}... metalloids, to moderately active nonmetals, to very active nonmetals, and to a noble gas."</ref>
| strongly nonmetallic<ref>[[#Mackin|Mackin 2014, p. 80]]</ref>
| {{indented plainlist|indent=0.9em|
* ◇ inert to nonmetallic<ref>[[#Johnson1966|Johnson 1966, pp. 105–108]]</ref>
* ◇ radon shows some cationic behavior<ref>[[#Stein1969|Stein 1969, pp. 5396‒5397]]; [[#Pitzer|Pitzer 1975, pp. 760‒761]]</ref>
  }}
|- style="vertical-align:top"
| scope="row" rowspan=3|[[Oxide]]s
|basic; some [[amphoteric]] or acidic<ref name="Porterfield">[[#Porter|Porterfield 1993, p. 336]]</ref>
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"|amphoteric or weakly acidic<ref>[[#Rochow1966|Rochow 1966, p. 4]]; [[#Atkins2006|Atkins et al. 2006, pp. 8, 122–123]]</ref>{{efn|Arsenic trioxide reacts with sulfur trioxide, forming [[arsenic sulfate|arsenic "sulfate"]] As<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>.<ref>[[#Wiberg|Wiberg 2001, p. 750]].</ref> This substance is covalent in nature rather than ionic;<ref>[[#Douglade|Douglade & Mercier 1982, p. 723]]</ref> it is also given as As<sub>2</sub>O<sub>3</sub>·3SO<sub>3</sub>.<ref>[[#Gillespie|Gillespie & Robinson 1959, p. 418]]</ref>}}
|acidic{{efn|{{chem|||NO|2}}, {{chem|||N|2||O|5}}, {{chem|||SO|3}}, {{chem|||SeO|3}} are strongly acidic.<ref>[[#Sanderson1967|Sanderson 1967, p. 172]]; [[#Mingos2019|Mingos 2019, p. 27]]</ref>}} or neutral{{efn|H<sub>2</sub>O, CO, NO, N<sub>2</sub>O are neutral oxides; CO and N<sub>2</sub>O are "formally the [[anhydride]]s of [[formic acid|formic]] and [[hyponitrous acid]], respectively viz. CO + H<sub>2</sub>O → H<sub>2</sub>CO<sub>2</sub> (HCOOH, formic acid); N<sub>2</sub>O + H<sub>2</sub>O → H<sub>2</sub>N<sub>2</sub>O<sub>2</sub> (hyponitrous acid)."<ref>[[#House|House 2008, p. 441]]</ref>}}

|acidic{{efn|{{chem|||ClO|2}}, {{chem|||Cl|2||O|7}}, {{chem|||I|2||O|5}} are strongly acidic.<ref>[[#Mingos2019|Mingos 2019, p. 27]]; [[#Sanderson1967|Sanderson 1967, p. 172]]</ref>}}

|metastable XeO<sub>3</sub> is acidic;<ref>[[#Wiberg|Wiberg 2001, p. 399]]</ref> stable XeO<sub>4</sub> strongly so<ref>[[#Klae|Kläning & Appelman 1988, p. 3760]]</ref>
|- style="vertical-align:top"
| few glass formers{{efn|Metals that form glasses are: vanadium; molybdenum, tungsten; alumnium, indium, thallium; tin, lead; and bismuth.<ref name="Rao 2002, p. 22">[[#Rao2002|Rao 2002, p. 22]]</ref>}}
|style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"|all glass formers<ref>[[#Sidorov|Sidorov 1960, pp. 599–603]]</ref>
|some glass formers{{efn|Unclassified nonmetals that form glasses are phosphorus, sulfur, selenium;<ref name="Rao 2002, p. 22"/> [[carbon dioxide|CO<sub>2</sub>]] forms a glass at 40&nbsp;GPa.<ref>[[#McMillan|McMillan 2006, p. 823]]</ref>}}
|no glass formers reported
|no glass formers reported
|- style="vertical-align:top"
|ionic, polymeric, layer, chain, and molecular structures<ref>[[#Wells|Wells 1984, p. 534]]</ref>
|style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"|polymeric in structure<ref name="Pudd">[[#Puddephatt|Puddephatt & Monaghan 1989, p. 59]]</ref>
|{{indented plainlist|indent=0.9em|
* ◇ mostly molecular<ref name="Pudd"/>
* ◇ carbon, phosphorus, sulfur, selenium have 1+ polymeric forms}}

|{{indented plainlist|indent=0.9em|
* ◇ mostly molecular
* ◇ iodine has a polymeric form, [[Iodine pentoxide|I<sub>2</sub>O<sub>5</sub>]]<ref>[[#King1995|King 1995, p. 182]]</ref>}}

|{{indented plainlist|indent=0.9em|
* ◇ mostly molecular
* ◇ [[xenon dioxide|XeO<sub>2</sub>]] is polymeric<ref>[[#Ritter|Ritter 2011, p. 10]]</ref>}}
|- style="vertical-align:top"
| scope="row" |Compounds with metals
| alloys<ref name="Kneen"/> or [[intermetallic compound]]s<ref>[[#Yama|Yamaguchi & Shirai 1996, p. 3]]</ref>
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"|tend to form alloys or intermetallic compounds<ref>[[#Vernon2020|Vernon 2020, p. 223]]</ref>
| {{indented plainlist|indent=0.9em|
* ◇ salt-like to covalent or metallic: hydrogen†, carbon, nitrogen, phosphorus, sulfur, selenium<ref name="Vernon2020p220"/>
* ◇ mainly ionic: oxygen<ref>[[#Woodward|Woodward et al. 1999, p. 134]]</ref>
  }}
| mainly ionic<ref name="Cotton"/>
| simple compounds at STP not known{{efn|[[Disodium helide]] (Na<sub>2</sub>He) is a compound of helium and sodium that is stable at high pressures above 113&nbsp;GPa. Argon forms an alloy with nickel, at 140&nbsp;GPa and close to 1,500 K, however at this pressure argon is no longer a noble gas.<ref>[[#Dalton|Dalton 2019]]</ref>}}
|- style="vertical-align:top"
| scope="row" rowspan=3|[[Ionization energy]] (kJ mol<sup>−1</sup>)<ref name="AylwardIE">[[#Aylward|Aylward & Findlay 2008, p. 132]]</ref>&thinsp;‡
| low to high
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"|moderate
| moderate to high
| high
| high to very high
|- style="vertical-align:top"
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"| 376 to 1,007
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"| 762 to 947
| 941 to 1,402
| 1,008 to 1,681
| 1,037 to 2,372
|- style="vertical-align:top"
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"| average 643
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"| average 833
| average 1,152
| average 1,270
| average 1,589
|- style="vertical-align:top"
| scope="row" rowspan=3|[[Electronegativity]] (Pauling){{efn|Values for the noble gases are from Rahm, Zeng and Hoffmann.<ref name="Rahm">[[#Rahm|Rahm, Zeng & Hoffmann 2019, p. 345]]</ref>}}<ref name="AylwardEN">[[#Aylward|Aylward & Findlay 2008, p. 126]]</ref>&thinsp;‡
| low to high
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"| moderate
| moderate to high
| high
| high (radon) to very high
|- style="vertical-align:top"
| 0.7 to 2.54
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD"| 1.9 to 2.18
| 2.19 to 3.44
| 2.66 to 3.98
| ca. 2.43 to 4.7
|- style="vertical-align:top"
| average 1.5
| style="border-right:2px dashed #CDCDCD; border-left:2px dashed #CDCDCD; border-bottom:2px dashed #CDCDCD;"| average 2.05
| average 2.65
| average 3.19
| average 3.3
|}
<span style="font-size:95%">
† Hydrogen can also form alloy-like hydrides<ref name="Cao4"/><br />
‡ The labels ''low'', ''moderate'', ''high'', and ''very high'' are arbitrarily based on the value spans listed in the table</span>