Question

If you have 30 grams of oxygen, how many atoms are present?

Answer 1

Answer:

1 × 10²⁴ atoms O

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

30 g O

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of O - 16.00 g/mol

Step 3: Convert

$30 \ g \ O(\frac{1 \ mol \ O}{16.00 \ g \ O} )(\frac{6.022 \cdot 10^{23} \ atoms \ O}{1 \ mol \ O} )$ = 1.12913 × 10²⁴ atoms O

Step 4: Check

We are given 1 sig fig. Follow sig fig rules and round.

1.12913 × 10²⁴ atoms O ≈ 1 × 10²⁴ atoms O