A 3.00 mole sample of K_2S contains how many atoms of potassium?

• A. 1.81 × 10^{24} atoms
• B. 3.61 × 10^{24} atoms
• C. 9.03 × 10^{24} atoms
• D. 6.02 × 10^{23} atoms

Answer: (B)

Verified step by step guidance

1. Identify the chemical formula of the compound: K_2S, which means each formula unit contains 2 potassium (K) atoms and 1 sulfur (S) atom.
2. Determine the number of moles of potassium atoms in the sample by multiplying the moles of K_2S by the number of potassium atoms per formula unit: \$3.00 \text{ moles K}_2\text{S} \times 2 = 6.00 \text{ moles K atoms}$.
3. Recall Avogadro's number, which is \$6.022 \times 10^{23}$ atoms per mole, to convert moles of potassium atoms to number of atoms.
4. Calculate the total number of potassium atoms by multiplying the moles of potassium atoms by Avogadro's number: \$6.00 \text{ moles K} \times 6.022 \times 10^{23} \text{ atoms/mole}$.
5. Express the final answer in scientific notation to match the format of the given options.