If you're looking for some fun, messy science that your kids will LOVE, this activity is a good one! All you need for this play recipe is baking soda, water, vinegar, and food coloring. The supplies you need for making ice volcanoes are small bowls, balls that will sink, plastic wrap, and some room in the freezer.
Start with a small bowl and place a golf ball in the bottom. Line each bowl with plastic wrap so that the golf ball is underneath and the plastic comes up over the sides.
Fill the bowls with a mixture of water and baking soda (approximately 2/3 water and 1/3 baking soda). You can also add food coloring. (Make sure you pour enough of the mixture in so that it covers the ball or you'll end up with a hole through the middle of your ice volcano.)
Once frozen, let them thaw a little, pull the plastic wrap off and pry out the golf ball. This can be tricky. (The volcanoes that sit out a bit longer are easier to remove).
A squirt of vinegar ...
and watch them erupt.
Not only is the reaction fun to watch, but the volcanoes are also fun to play with when they are melting!