Final answer:
The wave nature of matter, including standing waves, explains the quantization of energy levels in electron orbitals.
Step-by-step explanation:
The wave nature of matter is responsible for the quantization of energy levels in bound systems, including electron orbitals. Standing waves, which remain constrained within a specific region of space, play an important role in understanding the electronic structure of atoms. These standing waves are analogous to the vibrating string that produces harmonics with an integer number, n, of half-wavelengths between two fixed end points. The quantization of energy levels in electron orbitals can be explained by the interference of matter waves, where only those states that interfere constructively are allowed to exist.