Helium

Helium is a chemical element, number 2 on the periodic table. It is the second most common element in the universe after hydrogen. Helium is the typical result of hydrogen fusion inside stars. Helium is highly non-reactive, being the first of the noble gases.

Helium was a typical component for a class T nebula, along with hydrogen and argon. 

Liquid helium was used for the engines of. 

The species that docked with the automated repair station before Enterprise in 2152 lived in a liquid helium atmosphere, with a temperature of &minus;270 &deg;C. 

Helium fusion enhancement was at the center of Doctor Timicin's studies to re-vitalize the Kaelon sun. 

An anomalous rogue comet investigated by the USS Enterprise (NCC-1701-D) in 2370 had an outer layer of gaseous hydrogen and helium. 

The destruction of the Caretaker's array by the USS Voyager in 2371 left vapor consisting of hydrogen, helium, mercury, and argon. 

The nucleogenic cloud being was composed mostly of hydrogen, helium, and hydroxyl radicals. 

Trajis Lo-Tarik, a hallucination created by Seven of Nine while Voyager was traversing a nebula in 2374, offered liquid helium in trade for a microfusion chamber.