What does "atomic number 85" mean?

a highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium

What is a synonym for "atomic number 85"?

Common synonyms include: astatine, at.

Rare ·Advanced level

Noun

1
a highly unstable radioactive element (the heaviest of the halogen series); a decay product of uranium and thorium wordnet