I’ve decided that Fridays will be our day for science. Although I may change my mind, because I do that a lot, the plan is for every other Friday to be a lesson from our BFSU curricula while alternate Fridays will be ‘fun with science’ day.
I really like BFSU and think the boys have learned a lot, even JD who is still a bit young for it. But I find the lessons to be just a bit short on WOW! factor. Our fun days will not necessarily relate to anything we are learning, they’ll just be (hopefully) fun.
This week we pulled out a birthday present EJ received almost two years ago!
The kit comes with envelopes of baking powder, citric acid, colored fizzy tub tablets, yeast, and vegetable oil. There are also stirrers, mixing cups, a tiny magnifying glass and an instruction/explanation booklet.
The boys had a blast!
This was your basic citric acid solution with baking soda added. They both knew what was going to happen but as you can see by their faces it still enthralled.
We talked about how the bubbles are caused by a chemical reaction between the citric acid and the baking soda and that the bubbles are filled with carbon dioxide gas. After using the citric acid solution we did several experiments to see what other liquids might be acidic. We tried orange juice (mildly acidic), milk (not acidic), oil (not acidic), and of course vinegar (very acidic). They boys noticed that the vinegar caused many more bubbles than the orange juice. They also tasted a tiny bit of the orange juice and found that it was like orange soda (except for the blechy baking soda taste).
Next we tried the fizzy tub tablets.
The blue cup contains 1/4 blue fizzy tub tablet and water. They loved that it made the water turn blue and also fizzed. We talked about what might be in the tablets which turns out to be baking soda and citric acid. We talked about the fact that when the two ingredients are added together as solids there is no chemical reaction but as soon as we add water and allow them to dissolve the bubbling is released.
Then we made a “volcano”. First we started with vegetable oil, then added water. This gave us a chance to talk about density and how the oil stays on top of the water in a layer because it is less dense. After adding the red tablet they noticed that the bubbles float up through the oil, but only the water became red.
Next we changed the experiment just a bit. First we added some red food coloring drops. This was really cool because the food coloring drops would remain suspended in the oil for several seconds to almost a minute before finally floating down to the water. Then we added baking soda and citric acid and watched as our volcano erupted again.
Next we did the “dancing raisins” experiment. This was one EJ had seen on Head Rush with Kari Byron (who can also be found on Geek Mom), as soon as I pulled out the raisins he knew what was going to happen. The raisins are denser than the water of course, and will sink to the bottom of the glass. As the citric acid and baking soda react, the carbon dioxide bubbles stick to the raisins. If enough bubbles stick, the raisins will float up to the surface. The bubbles then pop causing the raisins to drop back down to the bottom. They will do this over and over as long as your chemical reaction is happening which for us was at least ten minutes. We were pretty lucky that all of our raisins did dance.
After we finished our official experiments EJ went off to feed his lady bug and JD decided to mix up some solutions of his own. We even have a handful of fizzy tub tablets left so we’ll try them out in the bath tonight!
Although most of the ingredients are easily found in the grocery store, having the instructions really helped me keep the experiments going. The only issue we had was with the yeast which did not activate, but that was probably because we kept the kit for so long before using it. This is a fun kit that would be great for any kid from about 4/5 and up. I think we all enjoyed today’s SCI-FRI!