orthohydrogen

== English == === Etymology === From ortho- +‎ hydrogen. === Pronunciation === (Received Pronunciation) IPA(key): /ˌɔːθəˈhaɪdɹəd͡ʒ(ə)n/ (General American) IPA(key): /ˌoɹθəˈhaɪdɹəd͡ʒ(ə)n/ Rhymes: -aɪdɹədʒən Hyphenation: or‧tho‧hy‧dro‧gen === Noun === orthohydrogen (countable and uncountable, plural orthohydrogens) (physics) form of the hydrogen molecule (H2) in which the two nuclei have parallel spin; about 75% of natural hydrogen ==== Antonyms ====