Final answer:
J.J. Thomson's contribution to atomic models includes the discovery of the electron and the development of the Plum Pudding Model, which suggested the atom was composed of scattered electrons within a positive sphere. His research provided significant strides in atomic theory, earning him the Nobel Prize in Physics.
Step-by-step explanation:
The scientist J.J. Thomson made significant contributions to our understanding of the atomic model. In 1897, Thomson conducted experiments that led to the discovery of the electron, a small, negatively charged particle within the atom. He proposed the Plum Pudding Model, which depicted the atom as a sphere of positive charge with electrons, then called 'corpuscles,' scattered within it, similar to plums in a pudding. This model challenged Dalton's Atomic Theory, which had been widely accepted for nearly a century, by suggesting that atoms were not indivisible.
Thomson's discovery of the electron and his atomic model laid the groundwork for future models. Although his Plum Pudding Model was later superseded by Ernest Rutherford's nuclear atom model, Thomson's work was instrumental in advancing atomic physics. For his outstanding contributions, he received the Nobel Prize in Physics in 1906 and was knighted in 1908.
Thomson's work is a crucial piece in the historical development of atomic theory, which has since evolved with contributions from other scientists like Ernest Rutherford and Niels Bohr, leading to our current understanding of atomic structure based on quantum theory.