Radiochem query in the school parking lot

So, I saw this today after dropping off PharmKid at her elementary school - a great homemade car sun visor:

Natural isotopic abundance fun in the elementary school parking lot. Credit: DJ Kroll/Terra Sigillata

Do you know the answer? Actually, first things first: do you know what the question is asking? We'll give a little more information later. I have no idea who the teacher or parent is who has this visor - the school goes from kindergarten to 5th grade and while I think our kids are brilliant, I'm not sure they will know the answer to the question. I'll just say for now that this visor brought me back to my radioisotopes undergraduate class at the Philadelphia College of Pharmacy and Science where the late Dr. Grafton Chase asked us to calculate the amount of radioactivity in a cargo ship full of bananas.

Author: David Kroll

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  1. Curious if anyone else has thought about the provenance of this sign. I believe I have a good guess…

  2. Always wished in retrospect that I had taken a course from Grafton Chase when I had the chance.

    • Funny thing, John, was that when I was a high school student fielding all these biology and chemistry mailings from prospective schools, the PCP&S Toxicology curriculum stood out to me because of the unique classes we’d get – and I remember Chase’s Radioisotope Technology as one of them.

      It was a terrific education. Our semester project was to identify a radioisotope that had been created in his neutron howitzer. I ended up having bromine-83. He also gave me the confidence to work with cadmium-109 (for metallothionein determinations) and mercury-203 (for tissue distribution studies) later in my internship at SmithKline. I remember the odd looks I got from senior scientists there when I showed how I could confidently set the manual windows on our old scintillation counter and gamma counter.

      Much gratitude I owe to Dr. Chase.

  3. Thank you. I was planning to talk about this next Tuesday, and now I have a nice illustration to start out with.

  4. I assume this sign used to be part of a science fair exhibit. If so, that’s a thrifty/green person to reuse cardboard.