Don't you worry about the residual RADIUM
from the luminous dials?
The Big Bang Theory Season 2, Episode 1
bathed in the glow of their love
and the RADIUM
The Big Bang Theory Season 5, Episode 16
Madam Curie's discovery of RADIUM
turned out to have great potential...
The Big Bang Theory Season 1, Episode 2
♪ Of a RADIUM in a lead jar
The Big Bang Theory Season 12, Episode 23
...this is Madame Curie killing herself
by discovering RADIUM.
The Big Bang Theory Season 6, Episode 4