Science for Kids: Overnight Crystal Garden - Babble Dabble Do (uses epsom salts) Lots of great science experiments
Marshmallow Science Experiment-Color Change (from Fantastic Fun & Learning)
Teach your little Einstein how plants absorb water with this cabbage and food coloring experiment from "Paging Fun Mums"!
extension of an oobleck activity - Humpty Dumpty Science Activity from I Heart Crafty Things. Includes a Free Printable Worksheet in the Post.