Final answer:
The modern atomic model differs from Thomson's "plum pudding" model and Rutherford's nuclear model by incorporating Quantum Mechanics, showing that electrons exist in probabilistic orbitals rather than fixed orbits, and recognizing the complex structure of the nucleus including protons, neutrons, and even smaller particles like quarks.
Step-by-step explanation:
Evolution of Atomic Models
The current understanding of atomic structure significantly differs from both Thomson's and Rutherford's models. Thomson's "plum pudding" model suggested that electrons were scattered within a positively charged 'pudding,' making the atom a uniform sphere of charge where electrons occupy any position. With Rutherford's gold foil experiment, however, it became evident that there was a dense, positively charged nucleus at the center with electrons orbiting, similar to planets around the sun. This led to the nuclear model of the atom.
Modern atomic theory, influenced by the principles of Quantum Mechanics, posits that electrons do not travel in defined orbits but rather in probabilistic 'clouds' or orbitals. The exact position of an electron at any given time cannot be determined, which is a principal deviation from both Thomson's model and Rutherford's planetary model. Current models also explore subatomic particles within the nucleus, such as protons and neutrons, and even delve into the realm of quarks and other elementary particles, signifying a deeper understanding of substructures that constitute matter.
Rutherford initially hypothesized the presence of a positively charged proton and later the concept of a neutral neutron was formulated. Moreover, with the discovery of the neutron in 1932, the complexity of the atomic nucleus could be better explained, and questions like why the nucleus does not fall apart could be approached with the understanding of nuclear forces that hold protons and neutrons together, despite the repulsive electromagnetic force between the positively charged protons.