How many moles of Pb are present in 4.71 × 10^{21} Pb atoms?

• A. 0.782 mol
• B. 0.0782 mol
• C. 7.82 mol
• D. 0.00782 mol

Answer: (D)

Verified step by step guidance

1. Identify the given quantity: the number of Pb atoms is \$4.71 \times 10^{21}$ atoms.
2. Recall Avogadro's number, which is the number of atoms in one mole: \$6.022 \times 10^{23}$ atoms/mol.
3. Set up the conversion from atoms to moles using the relationship: \(\text{moles of Pb} = \frac{\text{number of Pb atoms}}{\text{Avogadro's number}}\).
4. Substitute the values into the formula: \(\text{moles of Pb} = \frac{4.71 \times 10^{21}}{6.022 \times 10^{23}}\).
5. Perform the division to find the number of moles of Pb (do not calculate the final value here, just set up the expression).