SB 3.11.2

sata eva padārthasya
 svarūpāvasthitasya yat
kaivalyaṁ parama-mahān
 aviśeṣo nirantaraḥ
sataḥ — of the effective manifestation; eva — certainly; pada-arthasya — of physical bodies; svarūpa-avasthitasya — staying in the same form even to the time of dissolution; yat — that which; kaivalyam — oneness; parama — the supreme; mahān — unlimited; aviśeṣaḥ — forms; nirantaraḥ — eternally.
Atoms are the ultimate state of the manifest universe. When they stay in their own forms without forming different bodies, they are called the unlimited oneness. There are certainly different bodies in physical forms, but the atoms themselves form the complete manifestation.