How did the development of the earliest idea about atoms differ from the later work of scientists?

The smallest unit of matter, which possesses the characteristics of an element is known as an atom. It comprises a dense core known as the nucleus and alignment of outer shells inhabited by orbiting electrons.  

The early concepts of the atom postulate that the atom is a solid or a hollow body comprising nothing within. However, the discoveries and work done by scientists afterward have proved that the atoms comprise the subatomic constituents, that is, the protons, electrons, and neutrons.  

water is used to store them because it would keep the radiation from getting out in the open and causing harm to the workers