Question

The atomic masses of the two stable isotopes of copper 63Cu29 (69.17 percent) and 65Cu29 (30.83 percent)â are 62.929599 and 64.927793 amu, respectively. Calculate the average atomic mass of copper.

Answer 1

Average atomic mass of copper is 63.545642 amu

Step-by-step explanation:

100 atoms of copper contains 69.17 number of
`Cu_(29)^(63)` atoms and 30.83 number of
`Cu_(29)^(65)` atoms.

Therefore average atomic mass of copper is given by-

`((69.17* atomic mass of Cu_(29)^(63))+(30.83* atomic mass of Cu_(29)^(65)))/(100)`

=
`((69.17* 62.929599 amu)+(30.83* 64.927793 amu))/(100)`

=63.545642 amu