Question

how many moles of gold atoms do $7.35 \times 10^{24}$ gold atoms constitute? express your answer in moles to three significant figures. number of moles = \boxed{} mol au

Explanation:

Step1: Recall Avogadro's number

Avogadro's number is \( 6.022 \times 10^{23} \) atoms per mole. The formula to find moles from number of atoms is \( \text{Moles} = \frac{\text{Number of atoms}}{\text{Avogadro's number}} \).

Step2: Substitute the values

We have \( 7.35 \times 10^{24} \) gold atoms. So, moles \( = \frac{7.35 \times 10^{24}}{6.022 \times 10^{23}} \).

Step3: Perform the calculation

First, divide the coefficients: \( \frac{7.35}{6.022} \approx 1.2205 \). Then, divide the powers of 10: \( 10^{24 - 23}=10^{1} = 10 \). Multiply these results: \( 1.2205\times10 = 12.205 \). Rounding to three significant figures gives \( 12.2 \).

Answer:

\( 12.2 \)