...this is Madame Curie killing herself
by discovering RADIUM.
The Big Bang Theory Season 6, Episode 4
Madam Curie's discovery of RADIUM
turned out to have great potential...
The Big Bang Theory Season 1, Episode 2
Don't you worry about the residual RADIUM
from the luminous dials?
The Big Bang Theory Season 2, Episode 1
♪ Six times ten to the eighth
atoms of RADIUM ♪
The Big Bang Theory Season 12, Episode 23
♪ If the half-life of RADIUM
should happen to pass ♪
The Big Bang Theory Season 12, Episode 23