Question

A laboratory worker uses a centrifuge and a powerful magnet to separate 0.32 grams of iron from a large blood sample. How many individual atoms of iron are in that sample? ​

Answer 1

To calculate the number of iron atoms in a 0.32 grams sample, one must first find the number of moles by dividing by iron's molar mass, and then multiply by Avogadro's number resulting in approximately 3.45 x 10^21 atoms.

Step-by-step explanation:

To find the number of iron atoms in a 0.32 grams sample, we first need to determine the molar mass of iron, which is 55.8 grams per mole according to the periodic table. By dividing the mass of the sample by the molar mass, we can calculate the number of moles of iron:

• Number of moles = mass of iron (g) / molar mass of iron (g/mol)
• Number of moles = 0.32 g / 55.8 g/mol ≈ 0.005738 moles

Then, we use Avogadro's number, which is approximately 6.022 x 1023 atoms/mole, to find the number of atoms:

• Number of atoms = number of moles x Avogadro's number
• Number of atoms ≈ 0.005738 moles x 6.022 x 1023 atoms/mole
• Number of atoms ≈ 3.45 x 1021 atoms

Therefore, the sample contains approximately 3.45 x 1021 iron atoms.