1. Find the molar mass of samarium (Sm):
* The molar mass of samarium is approximately 150.36 g/mol. You can find this on the periodic table.
2. Calculate the number of moles of samarium:
* Divide the given mass by the molar mass:
* Moles of Sm = 56.279 g / 150.36 g/mol ≈ 0.3744 mol
3. Use Avogadro's number to find the number of atoms:
* Avogadro's number is 6.022 x 10^23 atoms/mol.
* Multiply the number of moles by Avogadro's number:
* Number of atoms = 0.3744 mol * 6.022 x 10^23 atoms/mol ≈ 2.25 x 10^23 atoms
Therefore, there are approximately 2.25 x 10^23 atoms in 56.279 g of samarium.
