IS II students determined the salinity of a sample using evaporation. Clearly this is not a great method but it is good for them to practice a procedure and they better understand the concept of salinity in parts per thousand (S o/oo). They are able to calculate experimental error and discuss the reasons for it. The samples are placed in a drying oven overnight.
With apologies to the Jackson 5 . . . students in IS I did a neat lab that is courtesy of Advancing Science at Gettysburg (PA) College. Students used radiation detectors and Logger Pro to measure the background radiation and then the radiation counts from alpha, beta, and gamma sources. They shielded the sources with paper, plastic, aluminum foil, and lead. Quite an eye opener to see how energetic gamma particle are!
On the left, IS II students work on finding the settling velocity of one the their 8 sand samples. Instructions and some diagrams are shared with them via Google drive (hence the laptops). Students work in teams of 4 and they are really good at dividing the tasks and working together. Overall a great lab ( click here for instructions and here for the descriptions).
Today we (IS II students and I) reviewed the procedures for a multi-day lab where they collect qualitative and quantitative data on 8 unknown sand samples. They describe the samples and determine grain size, settling velocity, roundness, luster, and the terrigenous vs biogenous component. I then give them descriptions and they have to match their samples with the correct locations. This year the sands are from Bermuda, Galapagos Islands, Daytona Beach, Miami, Uruguay, San Diego, Maui, and Costa Rica. There is great detective work and students always enjoy seeing the sand under magnification.
IS I students investigated the Law of Conservation of Matter by reacting vinegar and baking soda and attempting to contain the products (that included carbon dioxide gas). Good way to show them that their results will be less than perfect (delay in putting balloon on bottle, diffusion of gas through balloon). The diffusion was interesting for them to see as the mass continued to drop as the bottle ad balloon sat on the electronic scale. Hard for them to believe that balloons are full of holes!
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.