To make the volcano, O(4) filled a plastic bottle 3/4 full with lake water. We then built the volcano around the bottle using beach sand. O put 2 tablespoons of baking soda and several drops of food coloring into the bottle. She then poured white vinegar into the volcano, and we watched the eruption.
This is the first year that we've had red lava...since O's favorite color is blue, we always have blue lava. This time she wanted the lava to be red, and she told me that red is the "proper" color of lava. Can you tell she's been studying volcanoes at school? :)
We erupted our volcano 3 times, so that E(1) would have a chance to measure the baking soda and pour the vinegar. She LOVED it!