Answer
$58.9\ g$ $Co$ has the greater number of atoms.
Work Step by Step
- 58.9g $Co$:
Molar mass ($Co$) = 58.9g/mol
Therefore: 58.9g $Co$ = 1 mol $Co$
- 58.9g $Cu$:
Molar mass ($Cu$) = 63.5g/mol
Therefore: $58.9g \times \frac{1mol}{63.5g} = 0.93$ moles.
Thus:
1 mol $Co$ > 0.93 moles $Cu$
So: the number of atoms in 58.9 g $Co$ is greater.
