"CANDIUM" LAB

Purpose:

• Use a Candium model to explain the concept of atomic mass
• Analyze the isotopes of Candium and calculate its atomic mass.

Materials: 

An assorted sample of Candium

A scale (ex: triple beam balance)

Procedure:

1. Obtain sample of Candium.
2. Seperate the sample into groups of different isotopes. (M&Ms, Skittles, Gobstoppers...)
3. Determine the total mass of each isotope.
4. Count the total number of each isotope. 
5. Record data and calculations in the data table, which includes the following:

• average mass of each isotope
• percent abundance of each isotope
• relative abundance of each isotope
• relative mass of each isotope
• average mass of each isotope

Discussion:

• Define the term isotope.

Isotopes are atoms of the same element that have different masses, due to different numbers of neutrons.

• Define the difference between percent abundance and relative abundance.

Relative abundance is the number of a specific group of isotopes compared to the overall total, while percent abundance is the percent of the specific group. (relative abundance/overall total)

• How to find average mass and relative mass:

To find relative mass- average mass of group/smallest average mass of all

To find average mass- weigh the group of isotopes all together, and divide by the number of isotopes in the group.

• Why is this a model for calculating atomic mass of actual elements?

This activity is a good model for calculating atomic mass of real elements because each isotope can have a different mass, although they are atoms of the same element. Not all atoms are exactly alike, but they average to make one atomic mass.

Conclusion:

Our value for relative mass was relatively similar to the the rest of the lab groups'. Percent error did cause  all of our outcomes to vary. Our error may have come from slight differences in weighing the samples and also from the different masses of the isotopes. This lab is a good way to become familiar with the concept of averaging the masses of different isotopes to create an overall atomic mass.

Our Data Table!

Candy:	Average Mass:	Percent Abundance:	Relative Abundance:	Relative Mass:
Sixlets	.82 g	35.7%	15	1 g
M&Ms	.87 g	16.6%	7	1.06 g
Skittles	1.05 g	23.8%	10	1.28 g
Gobstoppers	169 g	23.8%	10	2.06 g

Average of all = 1.09