the abbreviation for HELIUM.
The Big Bang Theory Season 7, Episode 3
"Helium."
The Big Bang Theory Season 2, Episode 5
Not quite accurate.
The Macy's balloons are filled with HELIUM...
The Big Bang Theory Season 4, Episode 24
Forget HELIUM. The real superfluid
is the fruit punch in this mug.
The Big Bang Theory Season 9, Episode 16