Disputatio:Hydrogenium

See disputatio at carbonium.

Also, for proton, electron, neutron, etc., these are the forms I suggest:

proton, protonis, n.

proton prota protonis protonum protoni protonibus proton prota protone protonibus

I suggest prota because that would be the Greek plural (the corresponding word in Latin would be protum). The other option for the pl. would be protona.

For the "-on" suffix, some Neolatinits use (the etymologically correct) -on -i, while others use (the more convenient) -on -onis. Again, this is pretty widespread, so whatever we go with, we have to accept the other too. These days I kind of lean towards the third declension option, even though it is less correct historically, because it is convenient to be able to distinguish in neutro "in neither" from in neutrone "in a Neutron." Or electri "of electrum" from electronis "of an electron."

For a fuller discussion, see disputatio:Crypton. --Iustinus 16:57 iun 28, 2005 (UTC)

Actually, I would like to contest the claim that the -on, -i inflection is the one that is etymologically correct. From what I have studied, I have to say that the etymological history of the -on suffix used for names of subatomic particles is much more complicated than it first appears. I have mapped out my findings here. (The OED's etymological sections found on the electron and -on entries were particularly helpful.) It amounts to this: Electron does not neatly derive directly from ήλεκτρον, but instead is a portmanteau of "electric ion," and yet the -on of electron was then conflated with the neuter termination -ον (and perhaps also with the participle ὄν), resulting in the creation of proton, neutron, and others. This composite etymology, combined with the fact that we write electronic (not just electric) and electronicus (not just electricus) and the Greeks now write ηλεκτρονικός and ηλεκτρόνιο (not just ηλεκτρικός and ηλέκτριο), compels me to suggest that this -on (corresponding to the modern Greek -ον-) is an entirely modern suffix, that is, one with no clear Classical antecedent.

As for the inflection of proton, -onis, n.: It is not difficult to see why someone would dislike it (as Myces does). Neuters do not normally behave like -on, -onis in Latin (if they do at all!), so it seems that in order to defend the proton, -onis, n. inflection, one has to say something like, "Well, Latin doesn't necessarily disallow it." But one could argue that proton, -onis is declined as if it were a Latinized form of πρῶτον (gen. πρότονος), a Greek substantive adjective of the σῶφρον type. Since πρωτόνιον (corresponding to πρωτόνιο) looks as if it were a diminutive form of such a πρῶτον, this argument is not completely farfetched! 142.167.80.123 12:00, 22 Aprilis 2011 (UTC) --Diaphanus.

'-on' in rebus chemicis is the true Greek neuter ending in only a few cases—'neon' for example—the rest, such as 'electron', carry on from when it came to mean "particle" in modern languages and in such cases is probably better rendered as regular -on, -onis (tho I still dont like it). In any case inventing an declension with an irregular nom.acc.pl. is probably not a good idea. Modern Greek, for what it's worth, uses πρωτόνιο (→ protonium) etc.—Myces Tiberinus 17:46 iun 28, 2005 (UTC)

Well, the intent was not so much to have an irregular declension as have a mixed declension that draws from the two common paradigms. Sort of like bos, deus, and many Greek-imported names and words.

I always figured that the reason why they named particles in -on was to make them part of the neuter 2d declension. Seems fitting for fundamental bits and pieces. -TCF

Yes, I agree that it probably would not be a good idea to use an inflection pattern that seems to wonder back and forth between stems (in -o and -on) and declensions (2 and 3) even within the same number (singular or plural) when -o and -on are Latin stems as well as valid transliterations of Greek stems. Bos and deus (and even vis and vas) do not do anything analogous because each word either takes forms from the same stem and declension, or its singular forms come from one stem while its plural forms come from another. The very common changes in stems in many Greek-imported names is really due to the fact that Latin lacks some of the analogous stem types that Greek has, e.g. stems in -eu as in Orpheus. Sticking with the -on stem seems best. - Diaphanus 156.34.214.107 21:21, 3 Iulii 2008 (UTC)