======Measuring Background Radiation======


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**Alternative titles:** Geiger Counter Background Radiation
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====Summary====                   
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====Procedure====  
  - Begin with an analogy: compare radiation detection to counting drops from a water sprinkler, emphasizing that results vary but follow an average.  
  - Introduce the concept of radiation, radioactive decay, and how a Geiger counter detects particles.  
  - Distribute Geiger counters to student groups.  
  - Have students measure background radiation by counting Geiger counter clicks for one minute. Record results in a class data table.  
  - Repeat the measurement two more times per group to analyze variation.  
  - Discuss whether results vary between trials and why (instrument error, natural variation, or counting error).  
  - Compare group averages, ranges, and patterns of clustering or pauses in clicks.  
  - Extend the activity by testing background radiation in different locations (indoors vs outdoors, higher floors vs basement).  
  - Optionally test shielding effects using paper, metal, or other materials.



====Links==== 
Using a Geiger counter - UNSW Physics: 
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📄 BACKGROUND RADIATION - STEM in the lab: [[https://inl.gov/content/uploads/2023/07/Background-Radiation-Grades-9-12-1.pdf]]\\


====Variations====
  * Compare measurements on sunny vs cloudy days to test environmental effects.  
  * Have all groups measure in the same location to check instrument variation.  
  * Rotate groups through multiple room locations to test whether building materials affect readings.  
  * Introduce a known radioactive source and measure how shielding changes detection.



====Safety Precautions====
  * Handle Geiger counters with care—do not attempt to disassemble them.  
  * Use only approved low-level demonstration sources, never unregulated radioactive materials.  
  * Wash hands after handling any materials used with the Geiger counter.  
  * Ensure students understand that natural background radiation is not harmful at these levels.




====Questions to Consider====
  * What is background radiation, and where does it come from? (Natural sources include cosmic rays, radon gas, terrestrial rocks, and isotopes in our bodies.)  
  * Why might Geiger counter results vary even in the same location? (Radiation occurs in random bursts, and instruments may differ slightly.)  
  * Why do scientists measure background radiation before testing radioactive samples? (To subtract natural levels and obtain accurate readings of the source.)  
  * Were the Geiger counter clicks evenly spaced or clustered? What does this tell us about radioactive decay? (It is random, not steady.)  
  * How might measurement accuracy improve? (Take longer measurements, repeat trials, and average results.)  
  * Why do people at higher elevations experience more background radiation than those at lower elevations? (Less atmospheric shielding from cosmic radiation.)