
And that is
the most common ELEMENT
The Big Bang Theory Season 7, Episode 3

The ELEMENT was found
because of you,
The Big Bang Theory Season 7, Episode 6

"What is the lightest ELEMENT on Earth
with no stable isotope?"
The Big Bang Theory Season 1, Episode 13

stable super-heavy ELEMENT.
The Big Bang Theory Season 7, Episode 10

is the ELEMENT of surprise.
The Big Bang Theory Season 7, Episode 12