orthohydrogen

[ awr-thuh-hahy-druh-juh n ]
/ ˌɔr θəˈhaɪ drə dʒən /

noun Physics, Chemistry.

the form of molecular hydrogen in which the nuclei of the two hydrogen atoms contained in the molecule have spins in the same direction.
Compare parahydrogen.

Origin of orthohydrogen

First recorded in 1925–30; ortho- + hydrogen

British Dictionary definitions for orthohydrogen

orthohydrogen
/ (ˌɔːθəʊˈhaɪdrədʒən) /

noun

chem the form of molecular hydrogen, constituting about 75 per cent of the total at normal temperatures, in which the nuclei of the atoms spin in the same direction Compare parahydrogen