Density

I got this idea here. But I didn't do as many layers. 

We started with honey for our bottom layer. 

Dish soap. 

Vegetable oil

We forgot that water was more dense than oil, so when we poured the water (dyed green) it of course when right through the oil. We dyed the rubbing alcohol orange and put that layer on top. Even tipping the bottle and swirling it around gently did not mix the liquids. 

Testing which evaporates faster. Water (green) or rubbing alcohol (yellow).