The answer is 3.39 mol.
Avogadro's number is the number of molecules in 1 mol of substance.
6.02 × 10²³ molecules per 1 mol.
2.04 × 10²⁴ molecules per x.
6.02 × 10²³ molecules : 1 mol = 2.04 × 10²⁴ molecules : x
x = 2.04 × 10²⁴ molecules * 1 mol : 6.02 × 10²³ molecules
x = 2.04/ 6.02 × 10²⁴⁻²³ mol
x = 0.339 × 10 mol
x = 3.39 mol
