Solved on Nov 21, 2023
Find the percent abundance of Cu-63 (62.9296 u) and Cu-65 (64.9278 u) given copper's atomic weight of .
STEP 1
Assumptions1. Copper is made up of two isotopes, Cu-63 and Cu-65.
. The atomic mass of Cu-63 is62.9296 u and that of Cu-65 is64.9278 u.
3. The atomic weight of copper is63.546 u.
4. The percent abundance of Cu-63 is x and that of Cu-65 is (1-x).
STEP 2
The atomic weight of an element is the weighted average of the atomic masses of its isotopes. The weights are the percent abundances of the isotopes. Therefore, we can write the equation for the atomic weight of copper as follows
STEP 3
We can simplify this equation by distributing the64.9278 to the terms inside the parenthesis.
STEP 4
Combine like terms.
STEP 5
implify the equation.
STEP 6
Subtract64.9278 from both sides of the equation to isolate the term with x.
STEP 7
implify the left side of the equation.
STEP 8
Divide both sides of the equation by -1.9982 to solve for x.
STEP 9
Calculate the value of x.
STEP 10
To find the percent abundance of Cu-63, multiply x by100.
STEP 11
Calculate the percent abundance of Cu-63.
STEP 12
The percent abundance of Cu-65 is (-x), so subtract x from.
STEP 13
Calculate the percent abundance of Cu-65.
STEP 14
To find the percent abundance of Cu-65, multiply the result by100.
STEP 15
Calculate the percent abundance of Cu-65.
The percent abundance of Cu-63 is69.15% and that of Cu-65 is30.85%.
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