It is named that because it uses quantum mechanics to describe the behavior of electrons in atoms. Here's why:

* Classical physics fails: Earlier models like Bohr's model were based on classical physics, but they couldn't explain many observed phenomena like the spectral lines of atoms.

* Quantum mechanics solves the problem: Quantum mechanics, developed in the early 20th century, revolutionized our understanding of the very small. It introduced the concept of quantization, meaning energy, momentum, and other properties can only exist in discrete values.

* Electrons as waves: Quantum mechanics treats electrons not just as particles, but also as waves. This explains their behavior in atoms and the formation of orbitals.

* Probabilistic nature: The quantum mechanical model describes the probability of finding an electron at a particular location around the nucleus, rather than providing a definite path as in earlier models.

In summary, the Quantum Mechanical Model is named that because it relies heavily on the principles of quantum mechanics to explain the structure and behavior of atoms.