One is this skittles experiment my friend Maria saw on facebook and forwarded to me.
What You Need:
Bag of skittles
Cup of warm water
Line the skittles on a plate and be sure to not put similar colors together or it will
run. Once setup slowly pour warm water. You start to see the colors coming out and make a rainbow/tie-dye effect.
Kept the kids busy and quiet for 30 minutes.