Answer:
See explanation
Step-by-step explanation:
The Greeks held the belief that atoms where spherical. However, they thought that atoms of elements where different for the different states of mater. Dalton brought about the idea that the atoms of the same element are exactly alike irrespective of the physical state of the system.
Dalton introduced the idea that chemical reactions result from rearrangement of atoms in molecules. This idea was not captured by the early Greeks.