Since you did not show any picture, I will be describing Dalton’s atomic theory. The scientist thought that the atom was the smallest particle in the universe is John Dalton. He established five theories relating atoms. One, elements are made of extremely small particles called atoms. Two, atoms of different element have different sizes, mass and physico – chemical properties. Three, atoms cannot be divided further, destroyed or created. It also follows the law of conservation of energy. Fourth, atoms can combine to form compounds. And lastly, in chemical reaction, atoms can be combined, separated or rearranged.