Answer:
Average atomic mass = 63.62 amu
Explanation:
Average atomic mass is the weighted average of the individual isotopes.
And thus the weighted average =
(0.6917×63+0.3083×65)⋅amu = ?? amu.
Note that we have not accounted for the less massive copper isotopes that would decrease this mass to the accepted value of
63.55 amu.
Hope this helps! Good luck!
