This afternoon we finished our series of lessons involving carbon dioxide (see previous posts), culminating with making a volcano. We have been looking at nomenclature cards for the parts of a volcano, and we have also been looking at our globe and talking about the ways in which volcanic activity creates and shifts our land masses.

We set up our experiment:

We placed a glass Coca-Cola bottle in one of my baking dishes. Katie used a funnel to transfer baking soda into the bottle.

Next, she put red food coloring into some vinegar.

We built the volcano outside. There are so many beautiful ways to build a volcano from scratch, but we elected to keep it on the simpler side. We started by taping over the “crater” (the hole of the bottle) so that no sand would get in during construction. I filled as much of the dish as possible with moist dirt, and then we used wet sand to shape the cone and to smooth out the sides.

Eric, with his cutie-pie new hairdo (see previous post from today), helped to make the volcano.

Once we had the volcano constructed, we took the tape off the crater, and we poured the red vinegar down the pipe where it mixed with the baking soda…

Boom! Volcanic eruption!

As soon as we were done, Katie was begging to repeat the experiment. “This time with green lava!” she exclaimed. We had to dismantle the volcano, wash the bottle, and rebuild—but that was okay with me. We usually aim to do our science experiments at least twice, if we can. Every experiment this week we have performed more than once, and I emphasize that this is what good scientists do. We can’t, after all, rely on just one experiment, or one set of data points. Good scientists hope to replicate their findings multiple times.

So we did it again! Green lava this time! We pretended this was a volcano from a different planet, to account for the green.

Carbon dioxide is so much fun! Check out that lava flow! Katie actually asked to do it a third time, with orange lava…but we postponed that until another time.  Maybe we can build it again tomorrow!