All-School Meeting Share:
Ice, Rocks, and Fossils; October 30, 2015

Written and Presented by 2nd – 5th Graders, Birches School

Investigations (science) has been very exciting recently. In the 2nd/3rd Grade classroom we learned more about the three states of matter: solid, liquid, and gas. We transformed a solid into a liquid using different methods of heat. We each got ice cubes, made predictions, and used different methods to melt our solid into liquid. We tested the melt time by: 1. placing the ice cube on the windowsill inside the classroom; 2. placing the ice cube outside in the sun; 3. using a container of hot water; 4. using a container of tap water; 5. using warm water; and 6. placing the ice cube outside on the playground slide. We found that increasing the temperature by differing degrees caused the ice cubes to melt at different rates. We made bar graphs of our results and found that the quickest method was the container of hot water: It took 4 minutes to melt! The longest method (putting ice cube on the playground slide) took over 20 minutes to melt!  We learned that we can transform matter by changing temperature.

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In the 4th/5th Grade classroom we are studying the chemical composition of rocks and fossils. We learned about the Law of Superposition, which means that the oldest rocks are on the bottom layer, the newest rocks are on the top, and there are many layers in between. Each layer has a different chemical composition: Scientists look at the makeup of these different layers of rocks and fossils in order to find the age of the planet. Scientists think that the earth is 4.567 billion years old! We learned about carbon dating and how when an animal or plant dies, it loses carbon-14 over time. We learned that C-14 has a half-life, so every 5,700 years it decays or breaks down. On the other hand, carbon-12 is stable over time and it does not break down. Because C-14 is so unstable, scientists use it to compare to the level of C-12, and then they are able to measure how long ago an organism died. Scientists think that life began on earth 3.9 billion years ago and that there were at least five major extinction events. We are building a geological timeline in our classroom with timeline cards from the volcanic Hadean time to the present day. We are creating cards depicting the various inhabitants of earth over geological time.

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