We did a fun experiment today using Bromothymol Blue (BTB), which is a chemical that changes color when exposed to acids or bases.  I purchased it on Amazon.com from a chemical supplier pretty inexpensively, and you only need to use a little – just put a small amount in a cup and add water. To set up the experiment, I set out several clear plastic cups and got out our various supplies.  I filled the cups half full with the BTB / water mixture and then let the kids take turns adding things to see what would happen.  The older kids created a table toRead More →

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 allRead More →