1. iLab Reactivity
http://ilabcentral.org/radioactivity
Chemistry
http://ilabcentral.org/radioactivity/nuclearenergy
CT Workshop July 2012
2.
3. What are the
scientists
measuring?
What instrument is
used in this picture?
4. Investigation
• What does a Geiger counter measure?
• What does it mean if the Geiger counter is
making more clicking sounds?
• What is meant by “Counts per minute” or
“Counts per second”?
• What is a microSievert per hour?
6. iLab Reactivity Learning Objectives
• Students will create a model of the radiation
levels based on data from the Fukushima
video, and use this type of model to predict
the radiation levels at 1 km from the power
plant.
• The purpose of the iLab is to gather data to
allow a model to be created.
Teaching note: Some students may need more direction to find the answers to the questions listed above. Radioactivity is typically measured by a Geiger counter (also called a Geiger-Mueller counter), which is an instrument that detects and measures ionizing radiation. Different models of Geiger counters detect alpha particles, beta particles, or gamma rays. When charged particles or photons from a radioactive material pass through the gas, the ions create a signal that can be measured, allowing the Geiger counter to count the number of radioactive particles or photons that pass through the tube. A visual readout keeps track of the number of radioactive particles or photons being detected by the Geiger counter (counts per minute, counts per second, or microSieverts per hour) An audio readout on the Geiger counter makes a "click" sound for each radioactive particle or photon detected.
Watch the video “Inside Fukushima's Nuclear Reactor Evacuation Zone with Geiger Counter” until time 2:10. Copy down the two data points provided by the video. Does the video generate any student questions?Teaching note: Some questions that may be asked:Are the radiation levels safe?Will the dogs get sick?Why are the traffic lights out?Why are the radiation levels changing?How high will the radiation levels get?
Teaching note: if modeling by hand, students can be guided to use two data points and the power function y = A*x^B. The value of B should be close to 2. Students may need to use logarithms to determine A and B. Students can be asked to analyze the goodness of fit by examining the sum of the squared errors of the model.
Students should use their model to predict radiation levels at 1 km from the power plant. What is the safety risk at that point?Students can present Fukushima models and safety risk predictions.
