Chemical Reactions: a Science Experiment

This year we're enjoying the General Science course written by Dr. Jay Wile.  TBear recently did an experiment on chemical reactions that was kind of fun... and funny.

The set-up was to boil a few leaves of red cabbage in some water, then add the bluish water to  vinegar in a 2L bottle.  Next, he was to put some baking soda into a 6-9" balloon.  He was supposed to attach the balloon to the top of the bottle without letting any of the baking soda fall into it just yet.  So while I boiled the cabbage for him, TBear went in search of a balloon.

 
Unfortunately all we had were those tiny water balloons.  Then TBear hit on the brilliant idea of a rubber glove from the barn.  I wasn't sure it was a brilliant idea yet : ), but it was an experiment, and the glove was about the right size, so why not.

 Pouring the bluish cabbage water into the vinegar

Getting that glove with the baking soda in it rubber banded to the top of the bottle was interesting. Here he is adding the baking soda from the glove into the blue vinegar

 Whoa!  The glove worked!  Apparently there was enough carbon dioxide produced to inflate the glove.  (The baking soda combined with the vinegar produced carbon dioxide, sodium acetate and water.)

And the more you shook the bottle to mix up the baking soda, the bigger the glove got.

 

Fortunately I took pictures because he was also supposed to notice the change in the color of the vinegar water from blue to pink and back to blue again as a second chemical reaction was taking place.  TBear commented on it, but then had to think about it when the question was asked. : )  The second reaction happened as the vinegar was used up.  Something from the red cabbage (anthocyanin) interacted with the vinegar to turn the water pink.  As the vinegar was used up in the baking soda reaction, the water returned to its blue color.

I love fun science!  I also love the creativity of TBear.  I never would have thought of the glove; I'd have just put the experiment off until after I'd found a balloon.

A Visit to the Aquarium

This year TBear has been studying marine biology for science. We used Swimming Creatures of the Fifth Day by Apologia, and loved it. At the end of each week's lesson, TBear wrote a paragraph about what he'd learned, and often did a related experiment. Writing and narrating about what he's learned is wonderful, but the highlight of the lessons was creating a clay replica of some of the creatures he studied.

TBear created an aquarium from a box by lining the top and sides with blue paper, and the bottom of it with yellowish paper. Each week, after he finished the unit, he would make a clay or paper replica of the creatures he studied. While it may have seemed redundant in addition to the narrating and writing, it very nicely solidified in his mind the anatomy of the creatures as he tried to recreate them accurately for his aquarium box.

Here are some pictures of the end result. He was very proud of it, and I thought it turned out pretty darned good too!


I love the clay squid on the right side, and the humpback whale breaching. TBear's favorite pieces were the sea lion on the rock (on top of the box), the squid, the nudibranch, and the bright pink sea anemone. :-)

I also really liked how the bright pink sea anemone turned out (next to the sponge on the left.) He used Sculpey oven bake clay to make most of the creatures. Because the oven is only set to about 275 degrees, and the baking only takes from 4 to 10 minutes depending on the density of the object, he just baked the creature with the pipe cleaners in it.


Recently, on Memorial Day weekend, TBear went camping in Boothbay with some friends. The small but impressive Maine State Aquarium in Boothbay was only a few miles down the road from the campground. On Sunday, Whit and I drove down to Boothbay, and my friend Sonia and I took TBear to the aquarium. (We were sad that TBear's friend came down with a fever about the time we arrived. He stayed behind in the camper with his dad and Whit, poor baby.) As we wandered around the aquarium, I was tickled to hear TBear sharing so much of what he remembered from his science.

We thought the sea anemones were pretty neat. All the creatures in this aquarium can be found in the Atlantic waters off our coast here in Maine.

One of the highlights was a touch tank with a few dogfish sharks and two skates in it. The dogfish shark acted just like a dog, pushing its snout up out of the water and wanting to be petted! The aquarium docent explained that they might have gotten the name dogfish because they like to hunt in packs, but I'm pretty sure it's because they like to be pet like a dog does. The docent explained that the shark's skin actually has a lot of nerve endings and it really does like the feeling of being stroked. It was a pretty interesting experience. We learned this year that dogfish sharks' skin feels rough if you pet them from snout to tail (and doesn't feel good to them) because it is made up of scales called dermal denticles, which are basically tiny, sharp spikes (i.e. "teeth") that point in the direction of the tail.

Finally, TBear spent some time at the shallow tank, which had starfish, sea cucumbers, scallops, horseshoe crabs, hermit crabs, spider crabs, and other small creatures that one could pick up and look at more closely. It was kind of interesting picking up the horseshoe crab. They tend to whip their tails forward as you turn them over in sort of an en garde position to defend their tender undersides.

I can't believe I didn't think to get a picture of the lobsters! One was distinctly half blue, half yellow due to a strange genetic anomaly kind of like albinism. The line of color went from eyes to tail with the left half being blue, and the right half yellow. While Whit and I have been diving for lobsters in the distant past, and we used a scale to determine whether they were "keepers" or not, I just learned that there is actually an upper size limit on lobsters. Their carapace has to measure between 3 1/2 and 5 inches for them to be keepers. Anything larger than 5 inches has to be tossed back. It takes about 7 years for a lobster to reach the 3 1/2 inch minimum carapace length. My guess is that because it takes so long for the lobsters to grow to a minimum "keeper" length, by returning lobsters over 5 inches to the sea, they're allowed to continue reproducing as long as they live (which can be decades), thus avoiding being overfished. (There are a LOT of lobsters being shipped out of Maine each year, as well as being consumed here.)

All in all, we thought the trip to the aquarium was a great way to wrap up our study of marine biology this year.