The atomic mass of Copper : 63.6166 amu
Further explanation
Given
Copper-63 is 69.17%
Copper-65 is 30.83%
Required
The atomic mass of Copper
Solution
The elements in nature have several types of isotopes
Atomic mass is the average atomic mass of all its isotopes
Mass atom X = mass isotope 1 . % + mass isotope 2.% ...
The atomic mass of Copper = 0.6917 x 63 + 0.3083 x 65
The atomic mass of Copper = 43.5771 + 20.0395
The atomic mass of Copper = 63.6166 amu