How many letters does the top answer for “german physicist who discovered x-rays and developed roentgenography (1845-1923)” have?

The most common answer is roentgen (8 letters).

Crossword clue: german physicist who discovered x-rays and developed roentgenography (1845-1923)

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

roentgen 8 letters wn-def

German physicist who discovered x-rays and developed roentgenography (1845-1923)

rontgen 7 letters wn-def

German physicist who discovered x-rays and developed roentgenography (1845-1923)