How many moles are present in 2.85 × 10^{20} atoms of iron (Fe)?

• A. 1.71 × 10^{-3} mol
• B. 6.02 × 10^{23} mol
• C. 2.85 × 10^{-20} mol
• D. 4.74 × 10^{-4} mol

Answer: (D)

Verified step by step guidance

1. Identify the given quantity: 2.85 \times 10^{20} atoms of iron (Fe).
2. Recall that 1 mole of any substance contains Avogadro's number of particles, which is 6.022 \times 10^{23} atoms/mol.
3. Set up the conversion from atoms to moles using the relationship: moles = \frac{\text{number of atoms}}{\text{Avogadro's number}}.
4. Substitute the values into the formula: moles = \frac{2.85 \times 10^{20}}{6.022 \times 10^{23}}.
5. Perform the division to find the number of moles (do not calculate the final value here, just set up the expression).