parahydrogen

[ par-uh-hahy-druh-juhn ]

noun

, Physics, Chemistry.

1. the form of molecular hydrogen in which the nuclei of the two hydrogen atoms contained in the molecule have spins in opposite directions.

parahydrogen

/ ˌpærəˈhaɪdrədʒən /

noun

1. See orthohydrogen
   chem the form of molecular hydrogen (constituting about 25 per cent of the total at normal temperatures) in which the nuclei of the two atoms in each molecule spin in opposite directions Compare orthohydrogen

Word History and Origins

Origin of parahydrogen¹

First recorded in 1925–30; para- ¹ + hydrogen

Example Sentences

If they are oriented in opposite directions, it is parahydrogen.

From Project Gutenberg