Editing Electron configuration (section)

== Noble gas configuration ==
{{Further|Noble gas}}
'''Noble gas configuration''' is the electron configuration of [[Noble gas|noble gases]]. The basis of all [[chemical reaction]]s is the tendency of [[chemical elements]] to acquire [[Stable nuclide|stability]]. [[Main-group element|Main-group atoms]] generally obey the [[octet rule]], while [[transition metal]]s generally obey the [[18-electron rule]]. The [[noble gas]]es ([[Helium|He]], [[Neon|Ne]], [[Argon|Ar]], [[Krypton|Kr]], [[Xenon|Xe]], [[Radon|Rn]]) are less [[Electrical reactance|reactive]] than other [[Chemical element|elements]] because they already have a noble gas configuration. [[Oganesson#Predicted compounds|Oganesson is predicted]] to be more reactive due to [[Relativistic quantum chemistry|relativistic effects]] for heavy atoms.
:{|class=wikitable
! Period
! Element
! colspan="7"| Configuration
|-
| 1 || [[Helium|He]] || 1s<sup>2</sup>|| || || || || ||
|-
| 2 || [[Neon|Ne]] || 1s<sup>2</sup>||2s<sup>2</sup> 2p<sup>6</sup>|| || || || ||
|-
| 3 || [[Argon|Ar]] || 1s<sup>2</sup>||2s<sup>2</sup> 2p<sup>6</sup>||3s<sup>2</sup> 3p<sup>6</sup>|| || || ||
|-
| 4 || [[Krypton|Kr]] || 1s<sup>2</sup>||2s<sup>2</sup> 2p<sup>6</sup>||3s<sup>2</sup> 3p<sup>6</sup>||4s<sup>2</sup> 3d<sup>10</sup> 4p<sup>6</sup>|| || ||
|-
| 5 || [[Xenon|Xe]] || 1s<sup>2</sup>||2s<sup>2</sup> 2p<sup>6</sup>||3s<sup>2</sup> 3p<sup>6</sup>||4s<sup>2</sup> 3d<sup>10</sup> 4p<sup>6</sup>||5s<sup>2</sup> 4d<sup>10</sup> 5p<sup>6</sup>|| ||
|-
| 6 || [[Radon|Rn]] || 1s<sup>2</sup>||2s<sup>2</sup> 2p<sup>6</sup>||3s<sup>2</sup> 3p<sup>6</sup>||4s<sup>2</sup> 3d<sup>10</sup> 4p<sup>6</sup>||5s<sup>2</sup> 4d<sup>10</sup> 5p<sup>6</sup>||6s<sup>2</sup> 4f<sup>14</sup> 5d<sup>10</sup> 6p<sup>6</sup>||
|-
| 7 || [[Oganesson|Og]] || 1s<sup>2</sup>||2s<sup>2</sup> 2p<sup>6</sup>||3s<sup>2</sup> 3p<sup>6</sup>||4s<sup>2</sup> 3d<sup>10</sup> 4p<sup>6</sup>||5s<sup>2</sup> 4d<sup>10</sup> 5p<sup>6</sup>||6s<sup>2</sup> 4f<sup>14</sup> 5d<sup>10</sup> 6p<sup>6</sup>||7s<sup>2</sup> 5f<sup>14</sup> 6d<sup>10</sup> 7p<sup>6</sup>
|}

Every system has the tendency to acquire the state of stability or a state of minimum energy, and so chemical elements take part in chemical reactions to acquire a stable electronic configuration similar to that of its nearest [[noble gas]]. An example of this tendency is two [[hydrogen]] (H) atoms reacting with one [[oxygen]] (O) atom to form [[water]] (H<sub>2</sub>O). Neutral atomic hydrogen has one electron in its [[Valence electron|valence shell]], and on formation of water it acquires a share of a second electron coming from oxygen, so that its configuration is similar to that of its nearest noble gas [[helium]] (He) with two electrons in its valence shell. Similarly, neutral atomic oxygen has six electrons in its valence shell, and acquires a share of two electrons from the two hydrogen atoms, so that its configuration is similar to that of its nearest noble gas [[neon]] with eight electrons in its valence shell.