Answer:
1.54 × 10²⁴ atoms He
General Formulas and Concepts:
Math
Pre-Algebra
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Chemistry
Atomic Structure
- Moles
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
Stoichiometry
- Using Dimensional Analysis
Explanation:
Step 1: Define
[Given] 2.56 moles He
[Solve] atoms He
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
- [DA] Set up: [tex]\displaystyle 2.56 \ mol \ He(\frac{6.022 \cdot 10^{23} \ atoms \ He}{1 \ mol \ He})[/tex]
- [DA] Multiply [Cancel out units]: [tex]\displaystyle 1.54163 \cdot 10^{24} \ atoms \ He[/tex]
Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.54163 × 10²⁴ atoms He ≈ 1.54 × 10²⁴ atoms He
