In the context of the mole concept, 12.0 grams of carbon-12 represents which of the following?

• A. 12 moles of carbon-12 atoms
• B. 1 mole of carbon-12 atoms
• C. 0.5 mole of carbon-12 atoms
• D. 6.022 × 10^{23} grams of carbon-12

Answer: (B)

Verified step by step guidance

1. Recall the definition of a mole: 1 mole of any substance contains exactly \$6.022 \times 10^{23}$ entities (Avogadro's number).
2. Understand that the atomic mass of carbon-12 is defined as exactly 12 atomic mass units (amu), and by definition, 1 mole of carbon-12 atoms has a mass of exactly 12.0 grams.
3. Identify that the problem states 12.0 grams of carbon-12, which corresponds to the molar mass of carbon-12.
4. Use the relationship between mass, molar mass, and moles: \(\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}\).
5. Calculate the number of moles by dividing 12.0 grams by 12.0 g/mol, which will give the number of moles of carbon-12 atoms present.