User:Sandbh/Nonmetal rfc

Halogen nonmetals

 * Wikipedia (2020): Chemically, all s-elements except helium are highly reactive. Metals of the s-block are highly electropositive and often form essentially ionic compounds with nonmetals, especially with the highly electronegative halogen nonmetals.


 * Giansante (2020): "Most semiconductors…are composed by (n − 1)d10 metals of groups 11−15 (with empty or filled ns orbitals, such as Cu, Ag, Zn, Cd, In, Pb, and Bi, among others) and chalcogen, pnictogen, or halogen nonmetal atoms…


 * Vassilev & Vassilv (2016): As a general trend, only non-metals (especially halogen non-metals), alkaline and alkaline-earth lithophile elements, noble elements, and some chalcophile elements are commonly more enriched in algae than in coal."


 * Hui Wen at al. (2013): "−alkali-halides also enable the formation of non-stoichiometric (MnX or MXn) clusters by adding sin gle or multiple excess electrons, where, M=alkali metal atom, X=halogen nonmetal.


 * Daub & Seese (1996, p. 228): "A series similar to the electromotive or activity series exists for the halogen nonmetals."


 * Fernandez & Whitaker (1975, p. 149): "It was seen that the noble gases form a logical 'buffer' zone of relatively unreactive elements separating the very reactive alkali metals and the very reactive halogen nonmetals."


 * Leeds RD (1967, p. 33): "Ionic bonds are formed between metals and nonmetals; any alkali metal in group I will bond with any halogen nonmetal in group VII of the periodic table."

Moderately active nonmetals

 * Timm (1950): "Oxygen is a moderately active nonmetal and will combine directly with nearly every other element to form an oxide.
 * Gelender at al. (1959): "This oxidation may be accomplished by: (a) The use of suitable oxidizing agents for moderately active nonmetals."
 * Perlman (1970): "Between Groups I and VII there are gradations from active metals (Col. I) to less active metals to moderately active nonmetals to volatile nonmetals (halogens Col. VII)."
 * Wulfsberg (2000): "Most of the moderately active metals and nonmetals (the electropositive metals and electronegative nonmetals) are reduced from their oxides…using carbon."
 * Welcher (2001): "The elements change from active metals to less active metals, to metalloids, to moderately active nonmetals, to very active nonmetals, and to a noble gas."
 * Sorokhtin at al. (2007): "Nitrogen is a moderately active element, reacting weakly with natural inorganic compounds."

Unique and shared properties of H, C, N, O, P, S, Se

 * They appear sub-metallic (C, P,^ Se), coloured (S) or colourless (H, N, O). If solid, they are brittle (C, black P, S, Se) although these are all are known in either malleable, pliable or ductile forms.
 * Being sandwiched between the strongly electronegative halogen nonmetals and the weakly nonmetallic metalloids, their net chemical nature is moderately non-metallic. Hence the term moderately active nonmetals found in the literature.
 * Each one has an associated biogeochemical cycle, thus: hydrogen cycle; carbon cycle; nitrogen cycle; oxygen cycle; phosphorus cycle; sulfur cycle; selenium cycle.
 * Multiple vertical, horizontal and diagonal relationships
 * A proclivity to catenate peaks in this part of the periodic table (for H, see here). Silicon and boron do this too, but they are two of the elements most commonly recognised as metalloids, and are shown as such on the WP periodic table.
 * Uses in explosives and combustion; nerve agents; and organocatalysis.
 * A capacity to form interstitial and refractory compounds, in light of their relatively small atomic radii and sufficiently low ionization energy values

^ Black P, the most stable form in ambient conditions, is these days easily prepared.