Robert Millikan did his experiment by bombarding a thin sheet of beryllium with an alpha particle
newtest3
A Millikan atom model doesn't exist.
Antoine Lavoisier was a chemist and physicist in the late 1700's. Widely considered to be the Father of Chemisty, his contribution to the atomic model was the Combustion Theory and the beginnings of the Law of Conservation of Mass.
The model of the atom based on Quantum Theory is often called the "Quantum Mechanical Model" or the "Quantum Model." This model describes the behavior of electrons around the nucleus as probabilistic, rather than in fixed orbits.
Bohr
Niels Bohr's contribution to modern atomic theory was the proposal of a quantum model where electrons orbit the nucleus in specific energy levels, or shells. This model helped to explain the stability of atoms and the emission of specific wavelengths of light during electron transitions.
Ernest Rutherford is known for his famous gold foil experiment, which led to the discovery of the atomic nucleus and the proposal of the nuclear model of the atom. His work helped to refine the understanding of the structure of the atom and laid the foundation for the development of modern atomic theory.
a new model of the atom that describe electrons as being in a cloud
Niels Bohr's major contribution to atomic theory was his development of the Bohr model, which described the structure of the atom with electrons orbiting the nucleus in discrete energy levels. This model helped explain the stability of atoms and the spectral lines observed in their emission or absorption of light. Bohr's work laid the foundation for modern quantum theory and the understanding of atomic structure.
Quantum Theory
B, Quantum Theory!
Democritus's main contribution to physics was discovery of the atom. He devoted his life to finding out as much as possible to create what is thought to be the first atomic theory.
Niels Bohr is considered the founder of the modern atomic model.