You should now:
This is straightforward, but could be extended in any number of ways. Moreover, Planck's full derivation (and the Riemann Zeta function) would be very much worth revisiting. Experimentally, you should think carefully about how temperature is measured.
Just as examination of thermal radiation leads to the realization that the electromagnetic field must be composed of quanta (called photons), examination of sound waves in solids leads to the realization that these oscillations must also be composed of quanta (called phonons). Debye's derivation parallels Planck's work on blackbody radiation. Experimentally, this can prove to be an opportunity to deal with drift. You get to decide how you want to set this up, including what materials to use, how to add heat, how to measure temperature, and how much you need to do in order to show deviation from classical behavior.
Several experimental designs are available. Can you get one to work? It's up to you to examine the designs and chose one! In each the currents involved are quite small - leading to further discussion of techniques used in measuring small electrical signals.
The all-optical measurement techniques involved here are (almost) foolproof and notably precise. That, in itself, is an important lesson! Unlike small electrical signals, optical signals are immune to corruption from stray (environmental) fields (i.e., "noise"). Still, a little (optional) extra reading could enhance your work.
Examine this well-defined physical constant for yourself. Again, several experimental tricks are available to you.
As the class progresses, the selections listed above are extended to also include:
Extremely non-classical behavior, available for your examination.
This (Frank-Hertz Experiment) is straightforward, can be done using a variety of different gases, and can be extended in any number of ways. Moreover, there are many useful articles available in The American Journal of Physics. You may also wish to explore phenomena observable in a Crookes tube [Ref: pages 109-114 of Understanding the Properties of Matter, by Michael de Podesta, noting the Errata on page 112.] [Big Picture Ref: The mean free path, and the inelastic threshold.]
Well, that's not very particle-like -- is it?