Calculate the moles of Cu in 8.4×1021 atoms of Cu.
Express your answer using two significant figures.
To calculate the moles of Cu, we need to use Avogadro's number and the atomic mass of Cu.
1. Start by finding the atomic mass of Cu from the periodic table. The atomic mass of Cu is approximately 63.55 grams/mol.
2. Next, we need to convert the number of Cu atoms given into moles. To do this, use the following conversion factor:
1 mol Cu = Avogadro's number (6.022 x 10^23) atoms of Cu
3. Now, we can set up the calculation using the given information:
moles of Cu = (number of atoms of Cu) / (Avogadro's number)
moles of Cu = (8.4 x 10^21 atoms) / (6.022 x 10^23 atoms/mol)
moles of Cu ≈ 0.014 mol
Since we need to express our answer using two significant figures, we arrive at the final answer:
moles of Cu = 0.014 mol