Enter a clue or pattern or both:
The Clue
Element used in radiation research (9 letter answer)
The Answer
AMERICIUM
Tags
Notes
The answer AMERICIUM is so rare that it appears less than once every 2500 puzzles.
Definition
AMERICIUM as a noun:
1. (americium, Am, atomic number 95) = a radioactive transuranic metallic element; discovered by bombarding uranium with helium atoms