Sunday Science: Marshmallow Equations

My kids are very interested in chemistry, so I thought I’d teach them how to balance chemical equations.

First, we discussed how substances sometimes change when they are heated or combined, but the basic elements that make them up remain the same (conservation of mass). I gave them an example equation of 2 H2O = O2 + 2 H2.

I created 2 H2O molecules using colored marshmallows, and then explained that if the water molecules were broken apart they would recombine and instead of water could become O2  and H2. I took the first 2 “molecules” apart and demonstrated how they could recombine, and all the elements would be reused.

At this point my little ones were done, and they proceeded to make large sculptures from toothpicks and marshmallows which they then ate!

I then spent some more time explaining equation balancing to the older kids and working through them with the marshmallows. Afterwards they made some giant “molecules” which they had as a snack. Educational, tasty and fun!


If you try this here are some documents I found useful:

* Information on stable forms of gases (which I used to explain that “O”s would always try to combine into O2 and “H”s into H2):
http://www.jjstech.com/chfoforga.html

* A good tutorial on how to balance equations:

http://www.sky-web.net/science/balancing_chemical_equations.htm

* Equation balancing worksheets ready to print out (we printed a couple and worked through the easier equations):

http://chemistry.about.com/library/formulabalance.pdf

http://chemistry.about.com/library/formulabalance2.pdf

http://chemistry.about.com/library/formulabalance3.pdf

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