Half-Life and Forensic Archaeology Lab Recap

Today in class, we learned a new lesson on half-life. An overall summary of what half life is is that half life is the amount of time it takes for half of the substance to decay radioactively. We followed up the lesson with doing some practice problems. The problems would give you the mass, amount of time gone by, and the half life. Then, it would ask you to calculate the remaining mass left over after that time has gone by. For the most part, I thought this lesson was fairly easy, but I should just practice more with a variety of different types of half-life problems. I found this website that has many problems, including a short lesson to refresh my memory. I'll be doing some more practice on there.

http://www.m2c3.com/chemistry/VLI/M3_Topic2/M3_Topic2_print.html

In the second half of the class, we began a new lab dealing with what we just learned about half lives. We started the lab by measuring out a 24 cm by 24 cm paper and then cutting out 567 squares from it. This was extremely (!!!) tedious, but it did not actually take that much time. It was mostly just me trying to make the lines straight and the squares even. This lab's purpose was to give a demonstration on how radioactive decay works. We would scatter the squares onto a surface and then count the number of squares that have the colored side face up. Those squares represented how many "atoms" decayed. We would repeat this process 6 times, each time discarding those decayed atoms. Overall, I think this lab did give me a good model of how elements decay over time, losing their radioactivity.