Element 119 – Beanium

Purpose: To determine the atomic weight of an element by analogy.

Materials: container and cover, 500+ beans (navy, kidney, black-eyed), balance

Procedure:

  1. Select one of the numbered containers, each holding beanium atoms. The difference between the atom’s isotopes is very distinct. Each bean represents an isotope of the element beanium. Be certain to record the number of your container.
  2. Sort the beanium atoms into groups, each group representing a different isotope. Record the total number of atoms (beans) in your sample as well as the number of each type.
  3. Find the mass of each isotope to the nearest 0.01g and record in the data table. Return the beans (atoms) to the container carefully and cover.
  4. Note: Some beanium atoms have undergone natural fission. Please see instructor for a replacement.

Data Table:

Sample Number / Bean Type / Number of Beans / Mass of Beans
Black
Red
White
Total

Analysis:

  1. Determine the mass of a single beanium atom for each isotope (bean type) by dividing the total mass of each isotope by the number of atoms in that group. This will require three different equations SHOWING WORK!
  1. Determine the percent abundance for each isotope by dividing the number of atoms of each isotope by the total number of atoms in the container and multiplying by 100.This will require three different equations SHOWING WORK!
  1. Determine the average weighted mass of the element beanium based on the percent abundance of each isotope (#2) and its atomic weight (#1). This will require one equation SHOWING WORK!

Average Weighted Mass = (% as a decimal of isotope A)(mass of one atom of isotope A) + (% as a decimal of isotope B)(mass of one atom of isotope B) + (% as a decimal of isotope C)(mass of one atom of isotope C)…

  1. As a check on your answer #3, divide the total sample mass of all beanium isotopes from the container by the total number of beanium isotopes from the container. This answer should match the answer from #3.

Conclusion:

  1. What is the basic difference between isotopes of the same element, other than atomic mass?
  1. Why are the atomic masses on the periodic table not listed as whole numbers?
  1. Based on the periodic table, aluminum has an atomic mass of 27 when rounded off, but the six isotopes of aluminum have mass numbers of 24, 25, 26, 28, 29, and 30. Why are they all considered to be aluminum atoms?