The mass of 900. atoms of sodium(Na)

3.44 × 10⁻²⁰ g Na

General Formulas and Concepts:

Chemistry - Atomic Structure

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

= 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

the answer to your question is c