Definition of "orthohelium" []

• Form of the helium atom in which the spins of the two electrons are parallel. (noun)

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• "In orthohelium, on the other hand, the tracks of the two electrons lie in the same plane, the one being circular, while the other is elliptical."
• "It occurs in two different modifications: one is called parhelium, and is the more stable, and the other is called orthohelium - these were supposed at first to be two different substances."