One verse

Srimad Bhagavatam 3.11.2

3.11.2

सत एव पदार्थस्य स्वरूपावस्थितस्य यत् । कैवल्यं परममहानविशेषो निरन्तर: ॥ २ ॥

sata eva padarthasya svarupavasthitasya yat kaivalyam parama-mahan aviseso nirantarah

satah
of the effective manifestation
eva
certainly
pada-arthasya
of physical bodies
svarupa-avasthitasya
staying in the same form even to the time of dissolution
yat
that which
kaivalyam
oneness
parama
the supreme
mahan
unlimited
avisesah
forms
nirantarah
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.