How many atoms are present in 12 grams of carbon-12?

• A. 12 × 10^{23}
• B. 1.204 × 10^{24}
• C. 3.011 × 10^{23}
• D. 6.022 × 10^{23}

Answer: (D)

Verified step by step guidance

1. Identify the given quantity: 12 grams of carbon-12. This is important because the molar mass of carbon-12 is exactly 12 grams per mole.
2. Recall the definition of a mole: 1 mole of any substance contains Avogadro's number of particles (atoms, molecules, etc.), which is approximately \$6.022 \times 10^{23}$ particles per mole.
3. Since the molar mass of carbon-12 is 12 g/mol, 12 grams of carbon-12 corresponds to exactly 1 mole of carbon atoms.
4. Use Avogadro's number to find the number of atoms in 1 mole: multiply the number of moles by Avogadro's number, i.e., \$1 \text{ mole} \times 6.022 \times 10^{23} \text{ atoms/mole}$.
5. Conclude that the number of atoms in 12 grams of carbon-12 is \$6.022 \times 10^{23}$ atoms.