Day 151: Rate of Dry Ice Sublimation

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Students in IS I calculated the rate of sublimation of chunks of dry ice. For the longest time there was only one location in our county to purchase dry ice (local dairy main offices) and now we have to get it in the county to our west (Lancaster). We have to have a commuting teacher pick it up. Students enjoyed observing the dry ice in a beaker of warm water. They used the phase diagram to figure out the behavior of dry ice. They used Logger Pro to graph mass vs time and used the slope to come up with a sublimation rate in g/sec.




Day 137: The (not MTV) Real World

Screen shot 2014-04-04 at 10.55.21 AMAs IS II begin our unit on Plate Tectonics, we start with faulting and earthquakes. Today we calculated magnitude of quakes using a nomogram and began using Virtual Earthquake. As is often the case, the Earth helps me along by providing a real example of what we are studying. The Chilean quake has done just that. We check in on Google Earth and the USGS KML file to see the aftershocks; I share Twitter posts of a seismogram from Liverpool, England and plots of depth of quakes along the Peru-Chile trench that show the angle of subduction.

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Day 129: Porosity and Permeability Mayhem


Students in IS I are studying soils as part of their Big Grow 2014 and needed a clear way to understand porosity and permeability. I dusted off this lab that we have not done in over 10 years (when we used to teach Earth and Space Science and did a groundwater unit). I still use the columns for a beach sand lab where students determine settling velocity. Sometimes there are classic experiences in the classroom and this is one of them. I meant to take photos of the students but they had such trouble with the simple directions that I was putting out fires all period. I decided we will repeat the lab tomorrow to see if the results are different/more reliable.

Day 121: Radiometric Dating


Students in IS II used index cards to model the radioactive decay of Carbon-14 to stable Nitrogen-14. Keeping track of the increasing daughter isotopes and the decreasing parent isotope allowed them to see how the ratio of C:N relates to half-life and to absolute age. The index card helps them understand the limits of C-14 and other radiometric decay series.


We then got out the “cubium” atoms (wooden cubes with one side shaded). Each shake of the box represents the passing of time equal to one half-life of cubium. We have all seen this done with M&Ms and pennies but the twist here is that the decay is not a simple 1/2, 1/4, 1/8, etc. Students will conduct three full decay trials, graph the results, and interpret both the data and the graphs.

Day 104: Whiteboard Appreciation


Yesterday I was so wrapped up moving from table to table, helping groups of students with a number of activities they are doing, that I did not even know that an administrator was in the room, chatting with students and observing me. I used whiteboards to help out groups and then would leave the board and move on to another group with a new whiteboard. Every group had a different question. Great to have a visitor to the classroom see students engaged and respectful despite that fact that I was oblivious!

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