What is it about hydrogen that makes it different from the halides? What makes it only form di- and not tetra- or hexa- hydrides of the chalcogens?

  • $\begingroup$ @NicolauSakerNeto Tell me which of those answers you believe and I will accept it as a duplicate. $\endgroup$ – Dale Dec 19 '15 at 5:57
  • $\begingroup$ Why don't you just post it as an answer to the question? Btw, I cannot agree with the formation of binary compounds of helium and sulfur. $\endgroup$ – orthocresol Dec 19 '15 at 9:04
  • $\begingroup$ Opening a new identical question is the wrong approach. Post your answer in the other question. I do agree that I am not entirely satisfied with the answers given there (and some I believe to be wrong which I thus downvoted). However, it is a good question and it should attract the answers. I’m also going to flag this question for mod notice just in case they wish to take further action (e.g. merging). $\endgroup$ – Jan Dec 19 '15 at 14:38
  • $\begingroup$ @orthocresol helium and sulfur is a wild ideed indeed - meant more to provoke thinking than to be sought out. $\endgroup$ – Dale Dec 19 '15 at 14:45
  • 2
    $\begingroup$ This is a site where wrong answers are explicitly allowed to live. They may be downvoted, commented on but they should not be flagged and flags to wrong answers are generally rejected. The idea is that overall consensus puts wrong answers in the negative vote count range thereby clearly marking them as bad. $\endgroup$ – Jan Dec 19 '15 at 14:50

Alkalai Metals bond with Sulfur/Chalcogens in a 2:1 ratio and Hydrogen is behaving like an Alkalai Metal.

Lithium Sulflide = Li2S

Sodium Sulfide = Na2S

Potassium Sulfide = K2S

Rubidium Sulfide = Ru2S

Cesium Sulfide = Ce2S

Francium Sulfide = Fr2S

. . .

Hydrogen Oxide = H2O

Hydrogen Sulfide = H2S

Hydrogen Selenide = H2Se

Hydrogen Telluride = H2Te

If Hydrogen were like a Halogen, it would form H4S, and H6S. However Hydrogen doesn't obey the octet rule like halogens as it only needs to get rid of one electron, and yet it shares 2 electrons in a bond with Sulfur. That is exactly what the alkali metals do: they need to get rid of one electron and they share 2 with sulfur.

Na2S adopts the antifluorite structure, which means that the Na+ centers occupy sites of the fluoride in the CaF2 framework, and the larger S2− occupy the sites for Ca2+. -https://en.wikipedia.org/wiki/Sodium_sulfide

Thus an atoms lacking or exceeding by 2 tends to form 2:1 ratios with atoms lacking or exceeding by 1.

I wonder if He4S and He6S exist or if Helium would bond with Sulfur more like the alalai earth metals that bond to Sulfur in a 1:1 ratio.

Oxygen is really the problematic chalcogen: we are used to the Halogens behaving like hydrogen: See Dioxygen Diflouride and Hydrogen Peroxide. And then Hydrogen goes out and acts like an alkali metal.!


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