Question

The mass of 900. atoms of sodium(Na)

Answer 1

Answer:

3.44 × 10⁻²⁰ g Na

General Formulas and Concepts:

Chemistry - Atomic Structure

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

Explanation:

Step 1: Define

900 atoms Na

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of Na - 22.99 g/mol

Step 3: Convert

$900 \ atoms \ Na(\frac{1 \ mol \ Na}{6.022 \cdot 10^{23} \ atoms \ Na} )(\frac{22.99 \ g \ Na}{1 \ mol \ Na} )$ = 3.4359 × 10⁻²⁰ g Na

Step 4: Check

We are given 3 sig figs. Follow sig fig rules and round.

3.4359 × 10⁻²⁰ g Na ≈ 3.44 × 10⁻²⁰ g Na