Who among the following proposed that atom is indivisible ?

John Dalton, an English chemist, formulated the first modern scientific atomic theory in 1803. A central postulate of Dalton's theory was that all matter is composed of tiny, indivisible particles called atoms. He proposed that atoms are the smallest pieces of matter, containing no smaller parts, and that they cannot be created or destroyed. While ancient philosophers like Democritus and Acharya Kanad had previously theorized about indivisible particles (atomos or parmanu), Dalton provided the first evidence-based scientific framework for this concept. Later discoveries by scientists like J.J. Thomson and Ernest Rutherford eventually disproved the indivisibility of the atom by identifying subatomic particles such as electrons and the nucleus [2]. However, in the context of the initial scientific proposal of the indivisible atom, Dalton is the recognized figure.

Sources

1. [2] https://www.britannica.com/science/atomic-model