Answer: 6.31×10⁻³ moles Fe
Explanation:
To calculate moles when given atoms, we need to use Avogadro's number.
Avogadro's number: 6.022×10²³ atoms/mol
[tex](3.8*10^2^1 atoms)*\frac{mol}{6.022*10^2^3 atoms} =6.31*10^-^3 mols[/tex]
The atoms cancel out, and we are left with moles. There are 6.31×10⁻³ moles Fe.