How many atoms are present in a 40 g sample of carbon (atomic mass = 12.01 g/mol)?

• A. 2.01 × 10^{24} atoms
• B. 3.34 × 10^{23} atoms
• C. 6.02 × 10^{23} atoms
• D. 1.20 × 10^{25} atoms

Answer: (A)

Verified step by step guidance

1. Identify the given information: mass of carbon sample = 40 g, atomic mass of carbon = 12.01 g/mol.
2. Calculate the number of moles of carbon in the sample using the formula: \(\text{moles} = \frac{\text{mass}}{\text{atomic mass}} = \frac{40}{12.01}\).
3. Recall that one mole of any substance contains Avogadro's number of atoms, which is \$6.022 \times 10^{23}$ atoms/mol.
4. Calculate the total number of atoms by multiplying the number of moles by Avogadro's number: \(\text{atoms} = \text{moles} \times 6.022 \times 10^{23}\).
5. Express the final answer in scientific notation to compare with the given options.