Olivia Huie

[jrw1]October 26, 2007

“Snackium”

Purpose: The purpose of this experiment is to find the atomic masses of the natural isotopic mixtures.

Procedure:

  1. I made a table separated M&M’s, peanut M&M’s, and skittles, and told their quantity, weight, percent and percent mass contributed.
  2. Then I separated the different type of candy into the M&M’s, the peanuts M&M’s and the skittles.
  3. Then I counted how many were in each group and put them each into the table under quantity.
  4. Then I placed the candy into little containers and weighed each of them separately on the scale.I then recorded the weight of the candy on the table under weight.
  5. To get the percent, had to add all the amounts of the candy together, and divide the number of each by the total of all of them. Then I placed that under the percent column.
  6. Then I divided the weight and percent and got the percent mass contributed and I placed that under the column.
  7. Then we got the average of the class, and got the average percent mass contribution.

Data:

Quantity / Weight / Percent / % Mass Contribution
M&M’s / 42 / 1.01g / 40% / .404
Peanut M&M’s / 21 / 2.12g / 20% / .424
Skittles / 41 / 1.07g / 39% / .4173

Average Percent Mass Contribution: 1.25g

Calculations:

  1. Find the percent abundance of the pieces by dividing the individual [jrw2]piece quantity by the total number of snack pieces. Then multiply by 100% to get into percent form.
  2. Find the mass contribution of each type of snack by multiplying the mass of the snack type by the percent abundance (in decimal form- so if a piece’s abundance is 90%, multiply the mass by .90)
  3. Find the average atomic mass for the element by adding up all the mass contributions. From Calculation #2.

Conclusion: We found the atomic mass of snackium to be 1.25 grams. This was the average of everyone in the class.

Discussion of Theory: The theory that was demonstrated in this experiment was that the purpose of this lab was to find the atomic mass of snackium, and we did. The calculations show that the atomic mass is not very large. This experiment works because we just had to add all of the snacks together and divide them by the percent and the weight to get the percent mass contribution.

Experimental Sources of Error: You could have messed up the quantity of the candy and that would have thrown off the whole problem. The scale could have also been a few numbers off, which also would have thrown off the whole problem.

Questions:

  1. The weighted average atomic mass of the element is not the same as the mass of any of the pieces because you had to divide the mass by the percent to get the atomic mass and that would not equal to the mass.
  2. The average of the atomic mass is 1.25g. The error is .1g
  3. The percent error is .992g.
  4. The most abundant isotope for each element is the peanut M&M’s because it is .424g and that was the biggest one.

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