What are some quantum mechanics experiments that can be done with household items? I am interested in witnessing principals of quantum mechanics (Superposition, Quantum entanglement, Quantum tunneling, etc.) with simple household items.
The experiments that I have already tried are: 


*

*The double slit experiment (by shining a laser through a double slit to make an interference pattern)  

*Changing the color of fire by varying temperature and elements being burned

*Used two pairs of polarized sunglasses to alter to amount of light that passes through by rotating the lenses


Are there any other interesting ones that I could try?
 A: You could measure molar heat capacity of graphite at room temperature, it is much lower than that predicted by the classical equipartition theorem (Dulong-Petit law) due to quantum effects. Graphite is cheap, measurement of heat capacity does not seem too difficult.
A: Most probably, you did already many tunneling experiments at home - like many other people. Mechanical electric switches have layers of sulfides, oxides and other non-conducting material at their 2 contact zones. But still the resistor is very low, i.e. the lamp is working with normal intensity if the switch is closed. Many switches are constructed to scratch a little bit in order to break through these multi-atomic layers, but often both sides of the contact do not touch directly and are still separated by  non-conducting layers in state switched on. F.e. gold has an oxide layer, but this layer is limited to only a few atoms of thickness. So in order to work, mechanical switches need electrons to tunnel through non-conducting layers - and have also to tunnel at the surface barrier of the metal - nonmetal contact zones. So simply switching electric circuits is a common household tunnel experiment, that only fails if the corrosion/layers of the contact zones have become too thick.
