Learning Goal 13
Learning Goal 13: I can calculate the average atomic mass of an atom when given the percent composition and masses of the atom's isotopes.
Learning Criteria
1. I have memorized and can verbally describe and write out the definitions of the following terms: isotope, mass number, average atomic mass.
For example: If I was asked to define the term isotope, I would say that isotopes are different forms of the same atom (same # of protons), but with different masses and different numbers of neutrons.
2. I can distinguish beteen the mass number of an isotope and the atomic mass of an atom.
For example: If I was asked to distinguish between the mass number of an isotope and the atomic mass of an atom, I would explain that the mass numbers describe the individiual mass of each isotope of an atom while the atomic mass describes the average weighted mass of all of the isotopes of an atom.
3. I can calculate the average atomic mass of an atom when given the individual percent abundances and masses of its isotopes.
For example: If given the following masses and percent abundances for the atom Uranium (U), I would calculate the average atomic mass to be equal to be 238 amu.
Isotope Mass (amu) Percent Abundance (%)
U-234 234 0.01
U-235 235 0.71
U-238 238 99.28
(234)(0.01) + (235)(0.71) + (238)((99.28) = 238 amu
100
For example: If I was asked to define the term isotope, I would say that isotopes are different forms of the same atom (same # of protons), but with different masses and different numbers of neutrons.
2. I can distinguish beteen the mass number of an isotope and the atomic mass of an atom.
For example: If I was asked to distinguish between the mass number of an isotope and the atomic mass of an atom, I would explain that the mass numbers describe the individiual mass of each isotope of an atom while the atomic mass describes the average weighted mass of all of the isotopes of an atom.
3. I can calculate the average atomic mass of an atom when given the individual percent abundances and masses of its isotopes.
For example: If given the following masses and percent abundances for the atom Uranium (U), I would calculate the average atomic mass to be equal to be 238 amu.
Isotope Mass (amu) Percent Abundance (%)
U-234 234 0.01
U-235 235 0.71
U-238 238 99.28
(234)(0.01) + (235)(0.71) + (238)((99.28) = 238 amu
100
Learning Resources
Atomic Structure - Part 1 Chemistry Booklet: pp 25-34
(Student has a hard copy)
Video Tutorials:
Sapling
Subatomic Particles
Tyler Dewitt
Isotopes
Average Atomic Mass
Online Textbook: pp 104-106
hs.saplinglearning.com
(Student Log-in Required)
(Student has a hard copy)
Video Tutorials:
Sapling
Subatomic Particles
Tyler Dewitt
Isotopes
Average Atomic Mass
Online Textbook: pp 104-106
hs.saplinglearning.com
(Student Log-in Required)