Question

How many atoms of carbon are found in a 30.0 gram sample of the element?

Answer 1

Answer:

1.50 × 10²⁴ atoms C

Explanation:

Step 1: Define

Molar mass of C - 12.01 g/mol

Avagadro's Number: 6.02 × 10²³ atoms, molecules, formula units, etc.

Step 2: Use Dimensional Analysis

$30.0 \hspace{3} g \hspace{3} C(\frac{1 \hspace{3} mol \hspace{3} C}{12.01 \hspace{3} g \hspace{3} C} )(\frac{6.02(10)^{23} \hspace{3} atoms \hspace{3} C}{1 \hspace{3} mol \hspace{3} C} )$ = 1.50375 × 10²⁴ atoms C

Step 3: Simplify

We are given 3 sig figs.

1.50375 × 10²⁴ atoms C ≈ 1.50 × 10²⁴ atoms C