Final answer:
To calculate the number of calcium atoms in 56.5 g of calcium, divide the given mass by the molar mass of calcium to find the number of moles, then multiply by Avogadro's number to find the number of atoms.
Step-by-step explanation:
To calculate the number of calcium atoms in 56.5 g of calcium, you need to use the concept of moles. Since the molar mass of calcium is 40.078 g/mol, you can calculate the number of moles by dividing the given mass by the molar mass:
Number of moles = Mass of calcium / molar mass of calcium = 56.5 g / 40.078 g/mol ≈ 1.409 mol
Now, to convert moles to the number of atoms, you can use Avogadro's number, which is 6.022 × 10^23 atoms/mol. Multiply the number of moles by Avogadro's number:
Number of calcium atoms = Number of moles × Avogadro's number = 1.409 mol × 6.022 × 10^23 atoms/mol ≈ 8.483 × 10^23 calcium atoms.