WORKSHEET #36

Because some elements have different isotopes.
This means the same atom has different
numbers of neutrons.
Percentage of
category
Score
Percentage
(as decimal)
x Score
Tests
75%
80
60
Classwork
25%
90
22.5
Final Grade
Add the last column to get
answer
82.5
Percentage of Mass number Percentage
isotope
of isotope
(as decimal) x
Mass
Hydrogen-1
99%
1
.99
Hydrogen-2
0.8%
2
.016
Hydrogen-3
0.2%
3
.006
Average
Atomic Mass
Add the last column to get
answer
1.012
Iodine Average Atomic Mass = 126.86
Nitrogen Average Atomic Mass = 14.07
Cesium Average Atomic Mass = 132.85
In your body, there are 3 types of carbon.
Carbon-12, carbon-13 and carbon-14. The
most abundant is carbon-12 at 98%, carbon13 at 1%, and carbon-14 at 1%. What is the
average atomic mass for carbon?
2 points for correct answer
3 points for work