Erwin Schrodinger Austrian physicist, 1926
The quantum model

Quantum
It specifies the probability of finding an electron in the three-dimensional space around the nucleus and is based on solutions of the Schrodinger equation. This does not provide a precise path taken by an electron. This theory seeks to explain phenomena occurring at an atomic, and even smaller, scale. It provides a mathematical framework to study the behavior of subatomic particles, explaining phenomena such as entanglement and quantum tunneling
Electron Clouds
Instead of defining specific orbits like in Bohr's model, the quantum model describes electrons as existing in "clouds" or "orbitals." These clouds represent regions where there’s a high probability of finding an electron, rather than a fixed path.
Quantum ORbits
Electrons are described by a set of quantum numbers that indicate their energy levels, shapes of orbitals, and orientations. These quantum numbers help determine the electron’s behavior and the arrangement of electrons in an atom.
Uncertainty principle
Introduced by Werner Heisenberg, the uncertainty principle states that we cannot simultaneously know both the exact position and momentum of an electron. This means that the more accurately we know an electron's position, the less accurately we can know its momentum, and vice versa.
TRansitions
Electrons can still absorb or emit energy, but rather than jumping between fixed orbits, they transition between different energy states, represented by various orbitals. The energy changes correspond to the differences in energy between these states.
Wave Quality
The quantum model incorporates the idea that particles, like electrons, exhibit both wave-like and particle-like properties. This duality is fundamental to understanding how atoms behave at a microscopic level.