1. Avogadro's Number

Avogadro's number tells us the number of atoms or molecules in one mole of a substance. It's a very large number:

* 6.022 x 10²³ atoms/mole

2. Setting up the Calculation

We can use a conversion factor to go from the number of silver atoms to moles:

(1.8 x 10²⁰ atoms) * (1 mole / 6.022 x 10²³ atoms)

3. Calculate

Divide the number of atoms by Avogadro's number:

(1.8 x 10²⁰) / (6.022 x 10²³) = 2.99 x 10⁻⁴ moles

Answer: There are approximately 2.99 x 10⁻⁴ moles of silver atoms in 1.8 x 10²⁰ silver atoms.