Final answer:
The atomic model with a fuzzy electron cloud evolved from experimental evidence, notably quantum theory developed by scientists like Schrödinger and Heisenberg. Rutherford's experiment also contributed, leading to a model with a dense nucleus surrounded by a probability cloud of electrons instead of fixed orbits.
Step-by-step explanation:
The development of the atomic model with overlapping red and blue balls representing the nucleus and a surrounding fuzzy green cloud indicative of electron clouds is based on experimental evidence gathered over time. The discovery and understanding of quantum theory played a pivotal role in the formation of this model. Erwin Schrödinger, Werner Heisenberg, and Max Born were key contributors to quantum mechanics, which suggested the probability of electrons' locations as clouds, rather than fixed orbits.
Prior to this, the Bohr model presented an atom that consisted of a nucleus with electrons in defined circular orbits. However, through experiments such as Rutherford's gold foil experiment, it became clear that the nucleus was small and dense, with most of the atom being empty space. As scientists discovered the electron, proton, and later the neutron, this model simplified to show electrons orbiting a concentrated core of protons and neutrons. Yet, Bohr's fixed-path electrons did not fully explain atomic behavior at a quantum level.
In conclusion, the model with overlapping red and blue balls at its center and a fuzzy green cloud around them evolved from many iterations of atomic theory, with each step incorporating the experimental evidence available at the time, and especially embracing the principles of quantum mechanics to explain electron distribution around the nucleus.