How did the atom model change over time?

The 'plum pudding' model, the first model of the atom was created in 1904 by JJ Thomson, who believed that atoms were made entirely of negatively charged electrons.

Ernest Rutherford's 1911 gold foil experiment, in which he fired alpha particles at the foil and observed that some of them passed through and some bounced back, refuted this theory by suggesting the presence of a positive nucleus.

Since the negative electrons in Rutherford's cloud of negative electrons would be drawn to the positive nucleus and the atom would collapse in on itself, Niels Bohr proposed a model of the atom in 1913 in which the electrons were contained within quantized shells that orbited the nucleus.

Erwin Schrödinger, an Austrian physicist, combined the de Broglie equation with equations for wave behavior to produce a mathematical model for the distribution of electrons in an atom, which led to the creation of a quantum mechanical model of the atom in 1926.

Nonetheless, the current model, which uses quantized shells to contain the electrons, is most similar to the Bohr model of the atom.

https://tutor.hix.ai is the De Broglie equation.

The atom model evolved from the early ideas of indivisible particles to the current understanding of a nucleus surrounded by electrons. Key developments include Dalton's indivisible atom, Thomson's plum pudding model, Rutherford's nuclear model, and Bohr's planetary model. Quantum mechanics further refined the understanding, leading to the modern electron cloud model.