الإجابة

All praise be to Allah and may His blessings and peace be on His last messenger, Muhammad.

Although I prefer the use of a different translation to avoid that confusion, I must say that I don’t necessarily need to think that the translator attempted to mislead anyone. You want to first ask yourself about the meaning of the word atom itself, and whether it was used to refer to something other than the common meaning of it nowadays.

Etymologically speaking, here is the origin of the word atom, according to wikitionary.org: “From Old French atome from Latin atomus (“smallest particle”) from Ancient Greek ἄτομος (atomos, “indivisible”) from ἀ- (a-, “not”) + τέμνω (temnō, “I cut”).” According to Lisaan al-‘Arab, the most authoritative Arabic lexicon, authored in the seventh century A.H., the word atom means, amongst other things, that which is seen in the air when the sun rays enter through a window, and that which is not weighable; in other words, the smallest particle.

Based on the above, translating ذرة (dharrah) to atom is not technically mistaken. Now, neither word meant in the fifteenth century A.D. what they mean to us now. Please refer to my answer to the question about the egg-shaped earth for further information on scientific references in the Quran. Allah knows best.