Here is a quick and easy yet powerful experiment for para and diamagnetism that helps to provide evidence for quantum numbers.
I have my students use Orbital Viewer when learning about quantum numbers and their associated rules, electronic orbitals, and other quantum concepts. I have developed a worksheet that allows students to use Orbital Viewer to explore various concepts related to electronic orbitals.
Orbital Viewer is a fantastic program for displaying electronic orbitals. It is a great resource for teaching students about orbital shapes and the rules, nomenclature and notation of the quantum numbers n, l and m.