Question

Please help!! I don’t understand

Answer 1

Answer:

150 g Si

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Chemistry

Atomic Structure

• Reading a Periodic Table
• Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Stoichiometry

• Use Dimensional Analysis

Explanation:

Step 1: Define

[Given] 3.2 × 10²⁴ atoms Si

[Solve] grams Si

Step 2: Identify Conversions

Avogadro's Number

[PT] Molar Mass of Si - 28.09 g/mol

Step 3: Convert

1. [DA] Set up:                                                                                                       $\displaystyle 3.2 \cdot 10^{24} \ atoms \ Si(\frac{1 \ mol \ Si}{6.022 \cdot 10^{23} \ atoms \ Si})(\frac{28.09 \ g \ Si}{1 \ mol \ Si})$
2. [DA] Multiply/Divide [Cancel out units]:                                                            $\displaystyle 149.266 \ g \ Si$

Step 4: Check

Follow sig fig rules and round. Instructed to round to 2 sig figs.

149.266 g Si ≈ 150 g Si