Question

How many moles of silver atoms are there in 1.8 x 10 20 atoms of silver?

Answer 1

Answer is: 3·10⁻⁴ mol of silver atoms.
N(silver-Ag) = 1,8·10²⁰.
n(Ag) = N÷Na.
n(Ag) = 1,8·10²⁰ ÷ 6·10²³ 1/mol = 0,0003 mol = 3·10⁻⁴ mol.
N - number of atoms of silver.
Na - Avogadro number or Avogadro constant ( 6·10²³ mol⁻¹).¹
n - amount of substance.