Question

How many grams of present in 2.1x1026 atoms of cesium?

Answer 1

Answer:

46000 g Cs

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

Stoichiometry

• Using Dimensional Analysis

Explanation:

Step 1: Define

2.1 × 10²⁶ atoms Cs

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of Cs - 132.91 g/mol

Step 3: Convert

1. Set up:                       $\displaystyle 2.1 \cdot 10^{26} \ atoms \ Cs(\frac{1 \ mol \ Cs}{6.022 \cdot 10^{23} \ atoms \ Cs})(\frac{132.91 \ g \ Cs}{1 \ mol \ Cs})$
2. Divide/Multiply:                                                                                                $\displaystyle 46348.6 \ g \ Cs$

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

46348.6 g Cs ≈ 46000 g Cs