Question

What did Democritus believe an atom was?

Answer 1

In the 5th century, BC, Democritus of Abdera proposed that the atom was the tiniest indivisible quantity of stuff.

Explanation:

Our very name `"atom"` derives from the Greek word, `alphatauomuos`, which means `"uncuttable"` or `"indivisible"`. None of his writings survive, but he was the contemporary of Anaxagoras, Socrates, Hippocrates, and Pericles.

These days of course, we know that the atom CAN be sub-divided.