Floating Whiteboard Ink
Description:
I learned about this phenomenon when a teacher spilled their water on my whiteboard. Make sure to use a plate with an impermeable surface. It's a great phenomenon for intermolecular forces. Surface chemistry, temperature, color, ink type, polarity, salinity, and many more factors affect this phenomenon.
Web Resources: Drawing on Water - It is so surreal - YouTube
Limiting Reactant
Description: In this phenomenon both magnesium metal and hydrochloric acid are limiting reactants. I have used this in a chemistry class, framing it as "The Case of the Mixed Up Masses". I tell them that I added varying amounts of magnesium metal but I forgot to label the flasks. If done correctly they should get the curve seen below. I learned about this on the NSTA Resource page.
Web Resource: NSTA Stoichiometry Balloon Race