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