The quantum mechanical model of the atom was not developed by a single scientist, but rather emerged through the contributions of several physicists over a period of time. However, some of the key figures who played pivotal roles include:

* Erwin Schrödinger: He developed the Schrödinger equation, a fundamental equation in quantum mechanics that describes the behavior of electrons in atoms.

* Werner Heisenberg: He formulated the Heisenberg uncertainty principle, which states that it is impossible to simultaneously know both the position and momentum of an electron with perfect accuracy.

* Niels Bohr: While not directly involved in the development of the quantum mechanical model, Bohr's earlier atomic model laid the groundwork for the later quantum mechanical model.

* Max Planck: He introduced the concept of quantization of energy, which is a central tenet of quantum mechanics.

* Louis de Broglie: He proposed the wave-particle duality of matter, suggesting that electrons have wave-like properties.

Therefore, attributing the development of the quantum mechanical model to a single scientist would be inaccurate. It was a collaborative effort, building upon the groundbreaking work of many brilliant physicists.