Pennies, Pennies, PENNIES!

INTRODUCTION
The Pennium Lab will investigate the concept of atomic mass and how it was derived. You will be given a bag of pennies, you will discover how many different pennuim isotopes are in the bag. You will then determine the average atomic mass of pennium using the following equation: (average mass of isotope 1)(percent abundance of isotope1) + (average mass of Isotopes 2)(percent abundance of isotope 2)

 MATERIALS
-Pennies!
-Dimes!
-Nickels!
-and Quarters!
-Triple Beam Balance scale!


PROCEDURE PART 1
Step 1: Obtain a packet of pennies.
Step 2: Sort the pennies into two groups: pre 1982 and 1982 and newer.
Step 3: Measure the mass (in grams) of each stack of pennies. Record the mass (in grams) of each penny stack in a data table. Count the number of pennies in each stack.
Step 4: Measure the mass in grams of a half dollar, quarter, nickel, and dime. Record these values in a data table.
Step 5: Answer the questions below and then continue with Part 2


RESULTS OF PROCEDURE 1

 

	Pre	Posts	Nickels	Dimes	Quarters
Mass	2.5	3.04	5	2.3	5.7
#	11	14	1	1	1
Average Mass	.5g	.61g	1g	.46g	1.14g

Questions:
1. Does each penny have the same mass? No
2. Can you identify two "penny isotopes" bases on masses of the pennies? Pre penny Isotopes and Post penny Isotopes.
3. What does you data tell you about the relationship between mass of a penny and date of a penny. Make a generalization.  Pre 1982 weighs more than Post 1982 pennies.

PROCEDURE PART 2
1. Determine the average mass of Pre-1982 pennies. (Record Average) 3.03g
2. Determine the average mass of post- 1982 pennies. (Record average) 2.59g
3. Determine the percentage of your pennies that is pre-1982 and the percentage that is post- 1982. These percents should add up to 100%. What you have calculated is the percent abundance of each group of pennies(penny isotopes). Post is 44% and Pre is 56%
4. Lets say that the mass of a nickel is one CMU (coin mass unit). Use the mass of a nickel to calculate the mass of a half dollar, quarter, dime, pre-82 pennies, post 82 pennies. Again, Show all calculations, and record all data in a data table like shown.
5. Determine the average mass of Pennium in CMU's using the percent abundance of each pennium isotope (pre- 82 and post- 82) and the mass of each pennium isotope in CMU's.
(3.03 times .56) + (2.5 times .44) = 2.8 CMU

CONCLUSION
The post pennies have a bigger mass than the pre pennies. We derived the unit CMU by finding the mass of the nickel and used the Formula. The we used the Atomic mass average based to help find all of the elements in Atomic Mass.  So our conclusion is that the post pennies do have a bigger mass than the pre pennies.