Oxygen is mixed with this element for high-pressure breathing work, such as deep diving, because it is inert and less soluble in blood than nitrogen.  
This element transitions at much lower temperatures in its lighter-isotope liquid form because its nuclei are fermions and must form bosonic [BO-sawn-ik] pairs to condense.  As it is cooled past 2.2 K, the lambda point, it becomes a superfluid, called the liquid two form.  Oxygen is mixed with this element for high-pressure breathing work, such as deep diving, because it is inert and less soluble in blood than nitrogen.  FTP, name this element, the simplest of the noble gases with atomic number 2
This element transitions at much lower temperatures in its lighter-isotope liquid form because its nuclei are fermions and must form bosonic [BO-sawn-ik] pairs to condense.  
helium (prompt on "H-e")