Atomic Mass of Beanium
PSI Chemistry
Name_______________________________
Purpose :
 To calculate the average atomic mass of the new element Beanium.
Materials: Three or four different samples of beans, balance, pencil, and laboratory record
sheet and weighing dishes.
Procedure:
1) Obtain the sample of Beanium.
2) Separate the 3 or 4 isotopes (white beans, kidney beans, and brown beans etc) and
count how many of each are present. Record this number on your data table below.
3) Measure the mass of each isotope as a group (each bean type is an isotope of the
element Beanium). Record the data on your data table.
4) Fill in the rest of the information in the table according to the direction given in analysis
section below.
DataTable
Kidney beans
White beans
Brown beans
Totals
1) Total mass
2) Number
3) Average
mass (g)
4) Percent
abundance
5) Relative
abundance
6) Relative
mass
Analysis: Using the experimental data, record the answers to the following questions.
1) Calculate the average mass of each isotope by dividing its total mass by the number of
particles of that isotope. Record your data in the table.
2) Calculate the percent abundance of each isotope by dividing its number of particles by the
total number of particles and multiplying by 100.
3) Calculate the relative abundance of each isotope by dividing the percent abundance from
step 2 by 100.
4) Calculate the relative mass of each isotope by multiplying its relative abundance from step
3 by its average mass.
5) Calculate the atomic mass of all Beanium particles by adding the relative masses. This
average mass is the average atomic mass of Beanium.
6) Explain the difference between percent abundance and relative abundance. What is the
result when you total the a) individual percent abundances? And b) the individual relative
abundances?
7) The percent abundance of each kind of bean tells you how many of each kind of bean
there are in every 100 particles. What does relative abundance tell you?
8) Compare the total values for Rows 3 and 6 in the table. Why can’t the atomic mass in Row
6 be calculated the way the total for Row 3 is calculated?
9) Explain any difference between the atomic mass of your Beanium sample and that of your
neighbor. Explain why the difference would be smaller if larger samples were used.