Answer:
1.2 × 10⁻⁸ mol Pb
General Formulas and Concepts:
Math
Pre-Algebra
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Chemistry
Atomic Structure
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
Stoichiometry
- Using Dimensional Analysis
Explanation:
Step 1: Define
[Given] 7.2 × 10¹⁵ atoms Pb
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
- [DA] Set up: [tex]\displaystyle 7.2 \cdot 10^{15} \ atoms \ Pb(\frac{1 \ mol \ Pb}{6.022 \cdot 10^{23} \ atoms \ Pb})[/tex]
- [DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 1.19562 \cdot 10^{-8} \ mol \ Pb[/tex]
Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
1.19562 × 10⁻⁸ mol Pb ≈ 1.2 × 10⁻⁸ mol Pb
