Srimad Bhagavatam Canto 03, Chapter 11, Text 01

SB 3.11.1

maitreya uvaca
caramah sad-visesanam
 aneko ’samyutah sada
paramanuh sa vijñeyo
 nrnam aikya-bhramo yatah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The material manifestation’s ultimate particle, which is indivisible and not formed into a body, is called the atom. It exists always as an invisible identity, even after the dissolution of all forms. The material body is but a combination of such atoms, but it is misunderstood by the common man.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The atomic description of the Srimad-Bhagavatam is almost the same as the modern science of atomism, and this is further described in the Paramanu-vada of Kanada. In modern science also, the atom is accepted as the ultimate indivisible particle of which the universe is composed. Srimad-Bhagavatam is the full text of all descriptions of knowledge, including the theory of atomism. The atom is the minute subtle form of eternal time.
Srimad Bhagavatam Canto 03, Chapter 11, Text 02