The density of solid chromium (Cr) is 7.15 g/cm^3. How many atoms are present per cubic centimeter (cm^3) of Cr? (Atomic mass of Cr = 52.00 g/mol; Avogadro's number = 6.022 × 10^{23} atoms/mol)

• A. 8.28 × 10^{22} atoms
• B. 8.28 × 10^{22} atoms
• C. 8.28 × 10^{21} atoms
• D. 8.28 × 10^{22} atoms

Answer: (B)

Verified step by step guidance

1. Identify the given information: density of chromium (Cr) is 7.15 g/cm^3, atomic mass of Cr is 52.00 g/mol, and Avogadro's number is 6.022 × 10^{23} atoms/mol.
2. Calculate the number of moles of Cr in 1 cm^3 using the formula: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\). Here, mass is the density times volume (1 cm^3), so \(\text{moles} = \frac{7.15 \text{ g}}{52.00 \text{ g/mol}}\).
3. Use Avogadro's number to convert moles to atoms: \(\text{atoms} = \text{moles} \times 6.022 \times 10^{23} \text{ atoms/mol}\).
4. Substitute the moles calculated in step 2 into the equation in step 3 to find the number of atoms in 1 cm^3 of Cr.
5. Express the final answer in scientific notation to match the format given in the problem.