Hydrogen.
The Big Bang Theory Season 12, Episode 23
HYDROGEN was a little more
common or a little less common.
The Big Bang Theory Season 7, Episode 5
Didn't you say you're making
HYDROGEN sulfide gas?
The Big Bang Theory Season 4, Episode 4
- What are you doing in there?
- I'm making HYDROGEN sulfide...
The Big Bang Theory Season 4, Episode 4
they theoretically can separate
the HYDROGEN from the oxygen,
Breaking Bad Season 2, Episode 12