In the Pennium Lab, we were studying the concept of atomic mass and how it was derived by scientists. We were to develop our unit of measure, CMU (Coin Mass Units), to show how the system of AMU's is applied to finding the mass of other elements. Our observations at the beginning of this lab were as follows: there were many more pre-1982 pennies than those made in that year and after, a lot of math was going to be required to find our answers. Our hypothesis was that through doing a lab similar to how the system of AMU's were developed, we would come to better understand how that system of measure was formed and how it works now.
Materials:
- Packet of pennies, sorted into groups of pre-1982 and 1982 on
- Triple beam balance
- Quarter
- Nickel
- Dime
- Calculator
Procedure:
- After first sorting the pennies into their two respective groups, we measured each stack in grams, and then we recorded this data in a table, along with how many pennies were in each stack.
- We then proceeded to measure the mass of the quarter, nickel, and dime in grams; accordingly, this information also went into our data table.
- Our next step in the Pennium lab was to answer these questions: does each penny have the same mass; can you identify two "penny isotopes" based masses of pennies, and explain your answer; what does your data tell you about the relationship between mass of a penny date of a penny, make a generalization. Our answers to these questions were the following (in sequential order): No, each penny does not have the same mass; yes, you can identify different "penny isotopes" because all the pre-1982 pennies had a mass greater than those that were post-1981; the pennies from before 1982 have a greater mass than those made later, probably because of what they're made of.
- The next step we took was to determine the average mass of each group of pennies, followed by finding the percent abundance of the pennies.
- After we had finished that, we used the mass of our nickel, 5.19 grams, as 1 CMU, and found the respective masses of each group of coins in CMU's.
- The next step in lab was to determine the average mass of pennium by way of the percent abundance in grams as well as CMU's.
- The final step we took was to answer the final questions and make conclusions at the end of the lab; those quetions and conclusions were: make a statement about the average penny mass of pre-82, post-82, and the pennies in the packet; explain how you derived the unit "CMU"; using the idea explained in the aforementioned conclusions, how did scientists obtain the Atomic Mass Unit (AMU) to measure the mass of atoms of different elements; what is your weight in CMU's; write a statement that compares what you did in this lab to what scientists have done to find the average atomic masses of elements.
Data
Discussion
This lab was time consuming, but very informative. We found a great deal of new information, along with reiterating things we've been learning since freshman year. We spent some time talking about the order of events, after which we discussed the differences in weights.
Conclusion
As a result of this lab, we found that we did actually develop a better sense of how to measure in AMU's, and we enjoyed the time spent handling money!