How many atoms are contained in 0.230 g of sodium, Na? The mass of one sodium atom is 22.99 amu.

• A. 7.20 x 10¹¹
• B. 4.18 x 10³
• C. 6.02 x 10²¹
• D. 9.18 x 10⁴¹

Answer: (C)

Verified step by step guidance

1. First, understand that the problem requires you to find the number of atoms in a given mass of sodium. To do this, you need to use the concept of moles and Avogadro's number.
2. Calculate the number of moles of sodium in 0.230 g. Use the molar mass of sodium, which is approximately 23.99 g/mol. The formula to find moles is: \( \text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \).
3. Once you have the number of moles, use Avogadro's number to find the number of atoms. Avogadro's number is \( 6.022 \times 10^{23} \) atoms/mol. Multiply the number of moles by Avogadro's number to get the number of atoms: \( \text{atoms} = \text{moles} \times 6.022 \times 10^{23} \).
4. Ensure that your units are consistent throughout the calculation. The mass should be in grams, the molar mass in grams per mole, and the final result will be in atoms.
5. Review the calculation steps to ensure accuracy and check that the final number of atoms matches one of the provided options.