Paint that grows. Mix 1 cup flour, 3 tsp baking powder, 1 tsp salt, and enough water to make consistency of pancake batter. Divide into 4 parts and put in snack size Ziploc baggies along with food coloring. Squish it around to mix up the colors. Snip a tiny hole in the corner of the bag. Squeeze to paint and then pop paper in microwave for 30-45 seconds and watch the paint puff up and grow.
fizzing paint - mix baking soda with watercolors (you can use food coloring too) until it becomes a paint consistency. Put vinegar in jars with droppers. Kids paint pictures and then drip drop the vinegar onto their paintings to fizz them up! Super fun and easy!