One of the topics I know you are supposed to cover in early elementary science is the "States of Matter" (you know - solid, liquid, and gas), as well as the transitions between those states (you know - freezing, melting, vaporizing, and condensing). Earlier this week we had a fairly large snowfall, so it seemed that even the weather was hinting that it might be an ideal time to explore the solid-melting-to-liquid concept. At first I thought I would just bring some snow inside and let it melt, which qualifies as observational science since it is testable and repeatable and all that, but it seemed only slightly more exciting then observing paint dry. Thanks to Pinterest, I found an idea on the blog "Totally Tots" with a little more excitement to it.
First, we prepared four bowls. Tuesday was "write microscopically day" at our house, so if your vision is not 20/10 the labels read (from left to right, top to bottom) "plain snow," "with water", "with sugar," and "with salt." We wanted to see if adding things to the snow affected how quickly it melted.
Then we collected some fresh power and the kids made their predictions as to which bowl would liquefy first. In case you were concerned, the kids are pointing here, not flashing grade school gang signs. "With salt" and "with water" were the most popular choices.
For the next step, we added the snow to the bowls and mixed it up a bit. This is where our methodology broke down a little. My goal was to put the same amount of snow - two cups - into each bowl, but when you have four kids involved who vary quite a bit in age, precise and equal measurements are not to be had, so some bowls got a lot of snow and some got quite a bit less. I suspect this had a big impact on our results.
Finally, we set the timer for five minutes and began our observations. Nothing happened for a long time, but when your afternoon is broken into five-minute intervals time goes really fast (and NOTHING else gets done). Eventually, at one hour, the first bowl of snow was completely melted. This was the bowl the kids had predicted because they know about snow plows and salt trucks cleaning the roads. Five minutes later the bowl with the sugar added was finished. Another twenty-five minutes passed before the "plain snow" completed the solid-to-liquid process, and then another fifteen minutes after that the final bowl "with water" was totally melted.
Overall I would say it was a fairly successful experiment because now the kids are pretty clear on how snow melts to water when the temperature is above the freezing point and also that factors affect the melting process. However, if there ever is a next time for this experiment I will set the timer for a longer interval and use much less snow.
Happy wintertime science, everyone.