Answer:
6.3×10⁻³ moles of Cu
Explanation:
The relation is, that 1 mol of particles are contained by 6.02×10²³ particles.
This is Avogadro's number that explains that: one mole determines the number of fundamental units that are contained in a constant number but they do not depend on the type of material or the type of particle, and this quantity is 6.02 × 10²³
We can make a rule of three:
6.02×10²³ atoms are contained 1 in mol of Cu
Therefore, 3.8×10²¹ atoms will be contained in (3.8×10²¹ . 1) / NA = 6.3×10⁻³ moles
