Answer:
4.6 mol Si
General Formulas and Concepts:
Atomic Structure
- Reading a Periodic Table
- Moles
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
Stoichiometry
- Using Dimensional Analysis
Explanation:
Step 1: Define
[Given] 2.8 × 10²⁴ atoms Si
[Solve] moles Si
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
- [DA] Set up: [tex]\displaystyle 2.8 \cdot 10^{24} \ atoms \ Si(\frac{1 \ mol \ Si}{6.022 \cdot 10^{23} \ atoms \ Si})[/tex]
- [DA] Divide [Cancel like units]: [tex]\displaystyle 4.64962 \ mol \ Si[/tex]
Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
4.64962 mol Si ≈ 4.6 mol Si
