Answer:
2.1 × 10²⁴ atoms Pb
Explanation:
Avogadro's number: 6.022 × 10²³
Step 1: Find conversions
1 mol Pb = 6.022 × 10²³ atoms Pb
Step 2: Use Dimensional Analysis
[tex]3.5 \hspace{3} mol \hspace{3} Pb(\frac{6.022(10)^{23} \hspace{3} atoms \hspace{3} Pb}{1 \hspace{3} mol \hspace{3} Pb} )[/tex] = 2.107 × 10²⁴ atoms Pb
Step 3: Simplify
We have 2 sig figs.
2.107 × 10²⁴ atoms Pb ≈ 2.1 × 10²⁴ atoms Pb
