1. convert 8.43 x 1025 atoms of Fe to moles
2. convert 4.75 x 1024 molecules CO to moles
3. convert 2.43 x 1020 atoms Al to moles

The number of moles of Fe are, 139.9 moles.

The number of moles of CO are, 7.89 moles.

The number of moles of Al are, moles.

Explanation :

As we know that 1 mole of substance contains atoms or molecules.

Part 1:

As, atoms of Fe present in 1 mole

So, atoms of Fe present in mole

Thus, the number of moles of Fe are, 139.9 moles.

Part 2:

As, molecules of CO present in 1 mole

So, molecules of CO present in mole

Thus, the number of moles of CO are, 7.89 moles.

Part 3:

As, atoms of Al present in 1 mole

So, atoms of Al present in mole

Thus, the number of moles of Al are, moles.

the answer to your question is c