Question

Calculate the number of moles of cu in 2.0×1021 atoms of cu .

a) Moles = Avogadro's number / Number of atoms
b) Moles = Number of atoms / Avogadro's number
c) Moles = 2.0×10^21
d) None of the above

Answer 1

To calculate the number of moles of Cu in 2.0×10^21 atoms of Cu, we can use Avogadro's number.

Step-by-step explanation:

To calculate the number of moles of Cu in 2.0×10^21 atoms of Cu, we can use Avogadro's number. Avogadro's number is the number of atoms or molecules in one mole of a substance, which is approximately 6.022 × 10^23.

So, using the formula Moles = Number of atoms / Avogadro's number, we can calculate:

Moles = 2.0×10^21 / 6.022 × 10^23 = 3.32 × 10^-3 moles.

Therefore, the correct answer is (b) Moles = Number of atoms / Avogadro's number.