The ortho and para hydrogen possess:

Hydrogen exists in two isomeric forms:

(I) Ortho hydrogen: In this form, the spins of two nuclei are aligned in the same direction, either clockwise or anti-clockwise.
(II) Para hydrogen: In this form, two nuclei's spins are in opposing directions; if one is clockwise, the other is anti-clockwise, and vice versa.

Ordinary hydrogen is made up of 75% ortho-hydrogen and 25% para-hydrogen at ambient temperature. Because para-hydrogen is only stable at low temperatures, its percentage is higher than that of ortho hydrogen at low temperatures. Ortho and para-hydrogen possess the same electronic arrangement but the different spins of nuclei