ChemistryName______

Isotope Lab “Candium"Period ______

De Stigter

Purpose:

Mr. Willy Wonka has just discovered a new element found deep within the crust of the Earth. He named it Candium after his love for chocolate candy. In order to add “Candium” to the periodic table, Mr. Willy Wonka needs to determine the average atomic mass of “Candium”. Being busy with press conferences and meetings concerning this new element, Mr. Willy Wonka has asked this class to analyze the __known isotopes of “Candium” and to calculate its average atomic mass. Compensation is provided.

Procedure: - use the following table for your observations

1. Obtain a sample of “Candium”. Separate the ___ isotopes and record thenumbers for each type of isotope.

2. Next, determine the mass for each isotope and calculate the total mass in grams.

3. Calculate the average mass of each isotope by dividing its total mass by the number of particles of that isotope.

4. Calculate the % abundance of each isotope by dividing its number of particles by the total number of particles and then multiplying by 100.

5. Calculate the relative abundance of each isotope by dividing the % abundance (previous step) by 100.

6. Calculate the relative mass of each isotope by multiplying its relative abundance(from step 5) by its average mass.

7. Calculate the average mass of all Candium particles by adding the relative masses together. This average mass is the atomic mass of Candium. Include what lab group you are in. (show your work below)

8. Record the Atomic Mass of Candium from the other 5 lab groups.

Lab Group #1 – Atomic Mass of Candium ______

Members:

Lab Group #2 – Atomic Mass of Candium ______

Members:

Lab Group #3 – Atomic Mass of Candium ______

Members:

Lab Group #4 – Atomic Mass of Candium ______

Members:

Lab Group #5 – Atomic Mass of Candium ______

Members:

Lab Group #6 – Atomic Mass of Candium ______

Members:

Lab Group #7 – Atomic Mass of Candium ______

Members:

Lab Group #8 – Atomic Mass of Candium ______

Members:

9. Calculate your % error for the sample of Candium you have. To do this you will need to go to Mr. D and get the “Actual Value”. If you are more that 3% error, you will need to redo the lab over again.

% Error = ______

10. Calculate the % error of Candium for the entire class.

% Error = ______

Candium / Total
1. Number of Candium Isotopes
2. Total Mass (g)
3. Average mass (g)
4. % Abundance / 100% (should equal this…)
5. Relative Abundance / 1 (should equal this…)
6. Relative Mass / 7. Average Atomic Mass

Your Lab Group ____  Atomic Mass of Candium ______

Lab Report:

  1. Pretend that Candium has an atomic number of 19 and anatomic mass of 42.519. Draw one atom of Candium. Include the correct number of protons, neutrons, and electrons. Also create a chemical symbol fit for Candium, but don’t use one that has already been taken. Use colored pencils/markers.
  1. Assume there are 6 isotopes of gold (194-199). Determine the average atomic mass if the following % abundances are correct…(22.3%, 2.5%, 12.7%, 44.8%, 9.1%, 8.6%) (Note: This is a fictional problem)