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Science class is always most exciting when you can get hands-on. As teachers, there’s nothing more rewarding than seeing our students’ eyes light up and hearing them exclaim, “I get it!” I recently taught a lesson on volcanoes with a student teacher, Mr. H, and our eruption experiment turned out to be an incredible, inquiry-driven experience.<\/p>\n
“How does magma’s viscosity relate to the shape of a volcano?”<\/p>\n
The real fun of science isn’t just memorizing facts from a textbook; it’s about seeing, touching, and feeling the concepts for yourself. That’s why we decided to build a model volcano using everyday materials. This experiment might seem simple at first glance, but it’s surprisingly profound.<\/p>\n
We used just four ingredients: plaster, baking soda, laundry starch, and water. By simply adjusting the ratio of these four ingredients, we could completely change how the “magma” behaved and how viscous it was. It felt just like we were simulating real volcanic activity.<\/p>\n
The most fascinating part is the chemical reaction that occurs when you combine plaster (calcium sulfate: CaSO\u2084), baking soda (sodium bicarbonate: NaHCO\u2083), and water. As you might know, this reaction produces carbon dioxide (CO\u2082)! The CO\u2082 gas causes the mixture to puff up, just like a real volcano slowly swells before an eruption. Realizing that simple chemistry can lead to such grand natural phenomena is the true joy of science education.<\/p>\n
Mr. H and I went through countless attempts, changing the ratios over and over until we finally found the perfect recipe. It took us a good amount of time, but the feeling of accomplishment when we got it right was incredible. It was a perfect reminder of what scientific inquiry is all about.<\/p>\n
In this article, we’ll share the details of our successful volcano experiment, including the ratios we discovered and a step-by-step account of what happened!<\/p>\n
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For the plastic container, we used one we found at Daiso.<\/p>\n
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First, use an awl to make a hole in the bottom of the plastic container and cover it with cloth tape.<\/p>\n
Next, prepare the two different mixtures.<\/p>\n
For low-viscosity magma:<\/b> 1 ml of PVA glue + 30 ml of water<\/p>\n
For high-viscosity magma:<\/b> 10 ml of PVA glue + 15 ml of water<\/p>\n
Pre-mix these into two separate containers.<\/p>\n
\u2460<\/b> Thoroughly mix the PVA glue and water in the plastic container with a glass stirring rod.<\/p>\n
\u2461<\/b> Add 10g of plaster (from the zip-lock bag) to the mixture.<\/p>\n
\u2462<\/b> Mix the plaster, PVA glue, and water together thoroughly with the glass stirring rod.<\/p>\n
\u2463<\/b> Once it’s well-mixed, add 5g of baking soda and stir quickly to combine everything.<\/p>\n \u2464<\/b> Close the lid, flip the container upside down onto the tray, and immediately peel off the cloth tape.<\/p>\n \u2465<\/b> Observe the spread of the “lava” from directly above.<\/p>\n Repeat the entire procedure for both the high and low-viscosity mixtures.<\/p>\n Here’s what happens when you perform the experiment.<\/p>\n\n
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