Explore the fundamental principles of dimensionality in materials science through this comprehensive lecture by Prof. Antonio Castro Neto. Delve into how quantum mechanics and dimensionality shape the physics and chemistry of materials, from 0D atoms and molecules to 3D conventional materials. Gain insights into the black body radiation, Coulomb interaction, electron interactions, and magnetic systems. Examine mathematical objects, high spin ground states, effective mass in 2D, and the orientation of magnetism. Investigate quantum materials, quantum dots, and the role of topology and symmetry in materials science. Discover potential applications and ongoing research in the field of advanced materials for electronics.