It's the ATOMIC number for technetium.
The Big Bang Theory Season 6, Episode 8
Now, if you'll excuse me,
the father of the ATOMIC bomb...
The Big Bang Theory Season 4, Episode 3
Atomic magnets?
The Big Bang Theory Season 7, Episode 24
you get 14, which is
the ATOMIC number of...?
The Big Bang Theory Season 7, Episode 3
a woman is dividing the ATOMIC weight
of the best noble gas
The Big Bang Theory Season 9, Episode 8