Each hydrogen molecule (H2) consists of two hydrogen atoms linked by a covalent bond. If we neglect the traces of deuterium and tritium which could be present, each hydrogen atom consists of one proton and one electron. The proton has an associated magnetic moment, which we can treat as being generated by the proton's spin. The spins of the two hydrogen atoms can either be aligned the same direction (this is orthohydrogen) or in opposite directions (this is parahydrogen). The ratio between the o… (More on Parahydrogen)