Second grade chemists created an exothermic (heat producing) chemical reaction when they mixed 1/2 cup of 20 volume hydrogen peroxide (purchased at Sally’s Beauty Store), a few squirts of Dawn dishwashing soap, and 1 T yeast dissolved in 50 mL of warm water. Yeast was our catalyst. This lab provided an excellent opportunity to review lab safety. I also introduced chemical formulas.
Before the experiment, we learned that yeast is a one-celled living organism that reproduces by budding. It is in a dormant state in the package, but we can “wake” it up with warm water. Yeast is used to make bread dough rise as carbon dioxide is released. Click here to watch an animated video of yeast budding.
In some of the bottles, we changed variables. We didn’t place soap in one and and in another, we used cold water, rather than hot to dissolve the yeast. We added food coloring in one bottle, and it really looked like toothpaste!
Click here or here for experiment directions.
Click here to watch a larger eruption!
We learned that unleavened bread does not have yeast in it and therefore does not rise. The Bible mentions yeast 31 times. That would be an interesting study!
“You shall not eat leavened bread with it; seven days you shall eat with it unleavened bread, the bread of affliction (for you came out of the land of Egypt in haste), so that you may remember all the days of your life the day when you came out of the land of Egypt.
It was great fun introducing first grade’s matter unit with exploding pumpkins. We added two liquids (1/2 cup of warm water and 1/2 cup vinegar) and a solid (1 T of baking soda wrapped in half of a tissue) to make carbon dioxide gas. The Glad quart-sized bags filled quickly and most of them exploded! Before we began this investigation, we reviewed the Scientific Method and hypothesized what might happen when we mixed these chemicals. We gathered around tables as each set of lab partners completed the experiment. Click here to learn more. Try this at home and change some variables – more or less water, baking soda, or vinegar, cold water, various brands or sizes of bags, and then analyze your results.
Then we tried to catch the gas another way. I filled a balloon with baking soda, attached it to the rim of a water bottle, and turned it upside down. The baking soda fell into the vinegar inside the bottle. The balloon immediately filled with CO2. Click here to learn more.
This bag didn’t explode, how long will it stay inflated?
Safety first! We liked wearing goggles, and thought we looked a little like bugs!
Fourth grade biologists went for a walk around the KR property to investigate the ecosystems around campus. Before we left, we observed our millipedes, Billy and Jilly.
On our walk, Mrs. Price’s class discovered snails crawling all over the fall decorations in front of school. We placed them in the ecosystems that we created last week. (See previous post.)
After seeing some photos online, I wondered if it really was possible to grow cornstalks just by placing an ear of corn in water.
I rarely share personal news on my blog, but I am making an exception for this special occasion! My daughter and her fiancé are getting married on Friday – just the two of them at the courthouse in Chicago. When we began this journey over a year ago, we never envisioned the day looking like this, but it is the best choice for now, and we are focused on the joy! Thank you for indulging this mama!
I thought I would update this and add a photo that was taken after their courthouse wedding. It was rainy and cold, but nothing could dampen their happiness.
Caught this spider wrapping up its prey.
Kindergarten arachnologists learned more about spiders and their amazing webs. We drew a spider’s body, careful to draw two body parts (cephlothorax and abdomen), eight jointed legs attached to the cephlothorax, two helper legs (pedipalps), eight eyes, fangs, and spinnerets. Spiders are arachnids, not insects. Insects have six legs, three body parts, antennae, and often wings. Click here to learn more about spiders.
We practiced drawing orb webs. When I think about orb webs, I picture the planets orbiting the sun. It was fun to place our spider in the web and pretend it was catching flies. Imagine if there weren’t spiders to catch all the insects which make up at least 90% of the animal population!
We moved our lab outside and searched for spider webs by spraying them with a fine mist. (This turned out to be great exercise for our finger muscles.) The water sticks to the web, like dew, and makes the webs visible. I also threw some leaves into the web, and we observed how they stick to the strands. Sometimes, a spider will crawl down and realize the leaf is not food, and throw it out of the web.
Today was Cape Day benefiting Children’s Healthcare of Atlanta. Click here to learn more.
The perfect cape for the day!
Fourth grade biologists created forest floor ecosystems in collaborative teams. The biotic and abiotic factors in the ecosystem are interdependent. There is a community of pill bugs, beetles, and worms living in the ecosystems, each with its own niche. Students had the choice of grass seeds and two types of ground cover to add to the ecosystem. Other available materials included organic soil, sticks, decaying pieces of wood, leaf litter, pine cones, gravel, and pebbles. We designed our ecosystems on dry erase boards before we went “shopping” for supplies. They decided as a team how much water to add, where to place the ecosystem in their homeroom, and a name for their ecosystem. Their assignment is to maintain the ecosystems, so that the populations of organisms thrive. Click here to learn more about ecosystems.
Do you see something camouflaged on the stone?
It’s a praying mantis!