Enter a clue or pattern or both:
The Clue
PET scan particles (9 letter answer)
The Answer
POSITRONS
Tags
Notes
The answer POSITRONS is so rare that it appears less than once every 2500 puzzles.
Definition
POSITRON as a noun:
1. (positron, antielectron) = an elementary particle with positive charge; interaction of a positron and an electron results in annihilation