Editing Carbon group (section)

==Characteristics==
===Chemical===
Like other groups, the members of this family show patterns in [[electron configuration]], especially in the outermost shells, resulting in trends in chemical behavior:

{| class="wikitable" style="white-space:nowrap;"
|-
!''[[Atomic number|Z]]'' !! [[Chemical element|Element]] !! Electrons per [[Electron shell|shell]]
|-
| 6 || [[Carbon]] || 2, 4
|-
| 14 || [[Silicon]] || 2, 8, 4
|-
| 32 || [[Germanium]] || 2, 8, 18, 4
|-
| 50 || [[Tin]] || 2, 8, 18, 18, 4
|-
| 82 || [[Lead]] || 2, 8, 18, 32, 18, 4
|-
| 114 || [[Flerovium]] || 2, 8, 18, 32, 32, 18, 4<br/>(predicted)
|}

Each of the [[chemical element|elements]] in this group has 4 [[electron]]s in its outer [[electron shell|shell]]. An isolated, neutral group 14 atom has the ns<sup>2</sup>&nbsp;np<sup>2</sup> configuration in the ground state. These elements, especially [[carbon]] and [[silicon]], have a strong propensity for [[covalent bond]]ing, which usually brings the outer shell [[octet rule|to eight electrons]]. Bonds in these elements often lead to [[orbital hybridisation|hybridisation]] where distinct [[azimuthal quantum number|s and p characters]] of the orbitals are erased. For [[single bond]]s, a typical arrangement has [[tetrahedral molecular geometry|four pairs of sp<sup>3</sup> electrons]], although other cases exist too, such as three sp<sup>2</sup> pairs in [[graphene]] and graphite. Double bonds are characteristic for carbon ([[alkene]]s, {{CO2|link=yes}}...); the same for [[pi bond|π-systems]] in general. The tendency to lose electrons increases as the size of the [[atom]] increases, as it does with increasing atomic number.
Carbon alone forms negative [[ion]]s, in the form of [[carbide]] (C<sup>4−</sup>) ions.
Silicon and [[germanium]], both [[metalloid]]s, each can form +4 ions.
[[Tin]] and [[lead]] both are [[metal]]s, while flerovium is a synthetic, [[radioactive]] (its half life is very short, only 1.9 seconds) element that may have a few [[noble gas]]-like properties, though it is still most likely a post-transition metal. Tin and lead are both capable of forming +2 ions. Although tin is chemically a metal, [[α-tin|its α allotrope]] looks more like germanium than like a metal and it is a poor electric conductor.

Among main group (groups 1, 2, 13–17) alkyl derivatives QR<sub>''n''</sub>, where ''n'' is the standard bonding number for Q (''see'' [[IUPAC nomenclature of inorganic chemistry|lambda convention]]), the group 14 derivatives QR<sub>4</sub> are notable in being electron-precise: they are neither electron-deficient (having fewer electrons than an octet and tending to be Lewis acidic at Q and usually existing as oligomeric clusters or adducts with Lewis bases) nor electron-excessive (having lone pair(s) at Q and tending to be Lewis basic at Q).  As a result, the group 14 alkyls have low chemical reactivity relative to the alkyl derivatives of other groups.  In the case of carbon, the high bond dissociation energy of the [[C–C bond]] and lack of electronegativity difference between the central atom and the alkyl ligands render the saturated alkyl derivatives, the [[alkane]]s, particularly inert.<ref>{{Cite book |last=Crabtree |first=Robert H. |title=The organometallic chemistry of the transition metals |date=2005 |publisher=Wiley |isbn=978-0-471-66256-3 |edition=4 |location=Hoboken, N.J |pages=418}}</ref>

Carbon forms tetrahalides with all the [[halogen]]s. Carbon also forms [[carbon oxides|many oxides]] such as [[carbon monoxide]], [[carbon suboxide]], and [[carbon dioxide]]. Carbon forms [[Carbon disulfide|a disulfide]] an [[Carbon diselenide|a diselenide]].<ref>{{Citation|url = http://www.webelements.com/carbon/compounds.html|title = Carbon compounds|access-date = January 24, 2013}}</ref>

Silicon forms several hydrides; two of them are [[silane|SiH<sub>4</sub>]] and [[disilane|Si<sub>2</sub>H<sub>6</sub>]]. Silicon forms tetrahalides with fluorine ([[Silicon tetrafluoride|SiF<sub>4</sub>]]), chlorine ([[Silicon tetrachloride|SiCl<sub>4</sub>]]), bromine ([[Silicon tetrabromide|SiBr<sub>4</sub>]]), and iodine ([[Silicon tetraiodide|SiI<sub>4</sub>]]). Silicon also forms [[silicon dioxide|a dioxide]] and [[silicon disulfide|a disulfide]].<ref>{{Citation|url = http://www.webelements.com/silicon/compounds.html|title = Silicon compounds|access-date = January 24, 2013}}</ref> [[Silicon nitride]] has the formula Si<sub>3</sub>N<sub>4</sub>.<ref name="The Elements"/>

Germanium forms five hydrides. The first two germanium hydrides are [[germane|GeH<sub>4</sub>]] and [[digermane|Ge<sub>2</sub>H<sub>6</sub>]]. Germanium forms tetrahalides with all halogens except astatine and forms dihalides with all halogens except bromine and astatine. Germanium bonds to all natural single chalcogens except polonium, and forms dioxides, disulfides, and diselenides. [[Germanium nitride]] has the formula Ge<sub>3</sub>N<sub>4</sub>.<ref>{{Citation|url = http://www.webelements.com/germanium/compounds.html|title = Germanium compounds|access-date = January 24, 2013}}</ref>

Tin forms two hydrides: [[stannane|SnH<sub>4</sub>]] and [[distannane|Sn<sub>2</sub>H<sub>6</sub>]]. Tin forms dihalides and tetrahalides with all halogens except astatine. Tin forms monochalcogenides with naturally occurring chalcogens except polonium, and forms dichalcogenides with naturally occurring chalcogens except polonium and tellurium.<ref>{{Citation|url = http://www.webelements.com/tin/compounds.html|title = Tin compounds|access-date = January 24, 2013}}</ref>

Lead forms one hydride, which has the formula [[plumbane|PbH<sub>4</sub>]]. Lead forms dihalides and tetrahalides with fluorine and chlorine, and forms [[Lead(II) bromide|a dibromide]] and [[Lead(II) iodide|a diiodide]], although the tetrabromide and tetraiodide of lead are unstable. Lead forms [[Lead oxide|four oxides]], [[Lead(II) sulfide|a sulfide]], [[Lead selenide|a selenide]], and [[Lead telluride|a telluride]].<ref>{{Citation|url = http://www.webelements.com/lead/compounds.html|title = Lead compounds|access-date = January 24, 2013}}</ref>

There are no known compounds of flerovium.<ref>{{Citation|url = http://www.webelements.com/flerovium/compounds.html|title = Flerovium compounds|access-date = January 24, 2013}}</ref>

===Physical===
The [[boiling point]]s of the carbon group tend to get lower with the heavier elements. At [[standard pressure]], carbon, the lightest carbon group element, [[sublimation (phase transition)|sublimes]] at 3825&nbsp;°C. Silicon's boiling point is 3265&nbsp;°C, germanium's is 2833&nbsp;°C, tin's is 2602&nbsp;°C, and lead's is 1749&nbsp;°C. Flerovium is predicted to boil at −60&nbsp;°C.<ref name=gaseous>
Archived at [https://ghostarchive.org/varchive/youtube/20211211/F1sCiP72SY4 Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20170430135923/https://www.youtube.com/watch?v=F1sCiP72SY4&feature=youtu.be Wayback Machine]{{cbignore}}: {{cite web
|title=Discovering Superheavy Elements
|url=https://www.youtube.com/watch?v=F1sCiP72SY4
|first=Yu. Ts.
|last=Oganessian
|author-link=Yuri Oganessian
|publisher=[[Oak Ridge National Laboratory]]
|date=27 January 2017
|access-date=21 April 2017
}}{{cbignore}}</ref><ref name=EB>
{{cite web
|last=Seaborg |first=G. T.
|title=Transuranium element
|url=https://www.britannica.com/EBchecked/topic/603220/transuranium-element
|publisher=[[Encyclopædia Britannica]]
|access-date=2010-03-16
}}</ref> The [[melting point]]s of the carbon group elements have roughly the same trend as their boiling points. Silicon melts at 1414&nbsp;°C, germanium melts at 939&nbsp;°C, tin melts at 232&nbsp;°C, and lead melts at 328&nbsp;°C.<ref name="Table">{{Citation|last = Jackson|first = Mark|title = Periodic Table Advanced|year = 2001}}</ref>

Carbon's crystal structure is [[hexagonal crystal system|hexagonal]]; at high pressures and temperatures it forms [[diamond]] (see below). Silicon and germanium have [[diamond cubic]] crystal structures, as does tin at low temperatures (below 13.2&nbsp;°C). Tin at room temperature has a [[tetragonal crystal system|tetragonal]] crystal structure. Lead has a [[face-centered cubic]] crystal structure.<ref name = "Table"/>

The [[density|densities]] of the carbon group elements tend to increase with increasing atomic number. Carbon has a density of 2.26 g·cm<sup>−3</sup>; silicon, 2.33 g·cm<sup>−3</sup>; germanium, 5.32 g·cm<sup>−3</sup>; tin, 7.26 g·cm<sup>−3</sup>; lead, 11.3 g·cm<sup>−3</sup>.<ref name = "Table"/>

The [[atomic radii]] of the carbon group elements tend to increase with increasing atomic number. Carbon's atomic radius is 77 [[picometers]], silicon's is 118 picometers, germanium's is 123 picometers, tin's is 141 picometers, and lead's is 175 picometers.<ref name = "Table"/>

====Allotropes====
{{main|Allotropes of carbon}}
Carbon has multiple [[allotrope]]s. The most common is [[graphite]], which is carbon in the form of stacked sheets. Another form of carbon is [[diamond]], but this is relatively rare. [[Amorphous carbon]] is a third allotrope of carbon; it is a component of [[soot]]. Another allotrope of carbon is a [[fullerene]], which has the form of sheets of carbon atoms folded into a sphere. A fifth allotrope of carbon, discovered in 2003, is called [[graphene]], and is in the form of a layer of carbon atoms arranged in a honeycomb-shaped formation.<ref name = "The Elements"/><ref>{{Citation|url = http://www.graphene.manchester.ac.uk/|title = Graphene|access-date = 20 January 2013}}</ref><ref>{{Citation|url=http://www.webelements.com/carbon/allotropes.html |title=Carbon:Allotropes |access-date=20 January 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130117081035/http://www.webelements.com/carbon/allotropes.html |archive-date=2013-01-17 }}</ref>

Silicon has two known allotropes that exist at room temperature. These allotropes are known as the amorphous and the crystalline allotropes. The amorphous allotrope is a brown powder. The crystalline allotrope is gray and has a metallic [[Lustre (mineralogy)|luster]].<ref>{{Citation|last = Gagnon|first = Steve|url = http://education.jlab.org/itselemental/ele014.html|title = The Element Silicon|access-date = January 20, 2013}}</ref>

Tin has two allotropes: α-tin, also known as gray tin, and β-tin. Tin is typically found in the β-tin form, a silvery metal. However, at standard pressure, β-tin converts to α-tin, a gray powder, at temperatures below {{convert|13.2|C}}. This can cause tin objects in cold temperatures to crumble to gray powder in a process known as [[tin pest]] or tin rot.<ref name = "The Elements"/><ref name = "The Disappearing Spoon"/>

===Nuclear===
At least two of the carbon group elements (tin and lead) have [[magic nucleus|magic nuclei]], meaning that these elements are more common and more stable than elements that do not have a magic nucleus.<ref name="The Disappearing Spoon"/>

====Isotopes====
There are 15 known [[isotopes of carbon]]. Of these, three are naturally occurring. The most common is [[stable isotope|stable]] [[carbon-12]], followed by stable [[carbon-13]].<ref name="Table"/> [[Carbon-14]] is a natural radioactive isotope with a half-life of 5,730 years.<ref name = "Nature's Building Blocks"/>

23 [[isotopes of silicon]] have been discovered. Five of these are naturally occurring. The most common is stable silicon-28, followed by stable silicon-29 and stable silicon-30. Silicon-32 is a radioactive isotope that occurs naturally as a result of radioactive decay of [[actinides]], and via [[spallation]] in the upper atmosphere. Silicon-34 also occurs naturally as the result of radioactive decay of actinides.<ref name = "Nature's Building Blocks"/>

32 [[isotopes of germanium]] have been discovered. Five of these are naturally occurring. The most common is the stable germanium-74, followed by stable germanium-72, stable germanium-70, and stable germanium-73. Germanium-76 is a [[primordial nuclide|primordial radioisotope]].<ref name = "Nature's Building Blocks"/>

40 [[isotopes of tin]] have been discovered. 14 of these occur in nature. The most common is tin-120, followed by tin-118, tin-116, tin-119, tin-117, tin-124, tin-122, tin-112, and tin-114: all of these are stable. Tin also has four radioisotopes that occur as the result of the radioactive decay of uranium. These isotopes are tin-121, tin-123, tin-125, and tin-126.<ref name = "Nature's Building Blocks"/>

38 [[isotopes of lead]] have been discovered. 9 of these are naturally occurring. The most common isotope is lead-208, followed by lead-206, lead-207, and lead-204: all of these are stable. 5 isotopes of lead occur from the radioactive decay of uranium and thorium. These isotopes are lead-209, lead-210, lead-211, lead-212 and lead-214.<ref name = "Nature's Building Blocks"/>

6 [[isotopes of flerovium]] (flerovium-284, flerovium-285, flerovium-286, flerovium-287, flerovium-288, and flerovium-289) have been discovered, all from human synthesis. Flerovium's most stable isotope is flerovium-289, which has a half-life of 2.6 seconds.<ref name = "Nature's Building Blocks"/>