Crossword clue: a radioactive element of the alkali-metal group discovered as a disintegration product of actinium

The most common answer is fr (2 letters).

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

Possible answers

fr 2 letters wn-def

a radioactive element of the alkali-metal group discovered as a disintegration product of actinium

francium 8 letters wn-def

a radioactive element of the alkali-metal group discovered as a disintegration product of actinium