Prior to the Quran philosophers thought that the atom was the smallest indivisible component of matter. However today we know that this was false. Atoms are composed of electrons, neutrons and protons. And lately it turned out that those neutrons and protons are made of quarks…
However 1400 years ago the Quran contradicted the common knowledge of the time. It stated that the atom is not the smallest part:
[Quran 10:61] Whatever you may be doing, and whatever portion you may be reciting from the Quran, and whatever deed you may be doing, We [Allah] do witness when you are doing it. And nothing is hidden from your Lord (so much as) the weight of an atom on Earth and in heaven, not less than that nor more but is (written) in a clear record (the Preserved Tablet).