→Suggested distinguishing criteria: 3D electrical conductivity is not what the articles says, it is "some electrons". This is another rephrasing of delocalized electrons, so does not belong as "new", so removed.
:''Roman numerals such as III, V and VIII denote oxidation states''
Some nonmetallic elements exhibit [[oxidation state]]s that deviate from those predicted by the octet rule, which typically results in a valency of –3 in group 15, –2 in group 16, –1 in group 17, and 0 in group 18. Examples include [[ammonia]] N(III)HNH<sub>3</sub>, [[hydrogen sulfide]](II) H<sub>2</sub>S, [[hydrogen fluoride]](I) HF, and elemental xenon(0) Xe. Meanwhile, the maximum possible oxidation state increases from +5 in [[pnictogen|group 15]], to +8 in [[noble gas|group 18]]. The +5 oxidation state is observable from period 2 onward, in compounds such as [[nitric acid]] HN(V)O<sub>3</sub> and [[phosphorus pentafluoride]] PCl<sub>5</sub>.{{efn|Oxidation states, which denote hypothetical charges for conceptualizing electron distribution in chemical bonding, do not necessarily reflect the net charge of molecules or ions. This concept is illustrated by anions such as NO<sub>3</sub><sup>−</sup>, where the nitrogen atom is considered to have an oxidation state of +5 due to the distribution of electrons. However, the net charge of the ion remains −1. Such observations underscore the role of oxidation states in describing electron loss or gain within bonding contexts, distinct from indicating the actual electrical charge, particularly in covalently bonded molecules.}} [[Oxidation state#List of oxidation states of the elements|Higher oxidation states]] in later groups emerge from period 3 onwards, as seen in [[sulfur hexafluoride]] SF<sub>6</sub>, [[iodine heptafluoride]] IF<sub>7</sub>, and [[xenon tetroxide|xenon(VIII) tetroxide]] XeO<sub>4</sub>. For heavier nonmetals, their larger atomic radii and lower electronegativity values enable the formation of compounds with higher oxidation numbers, supporting higher bulk [[coordination number]]s.<ref name="Cox" />
