Moles of calcium = mass of calcium / molar mass of calcium
The molar mass of calcium is 40.08 g/mol. Therefore:
Moles of calcium = 169 g / 40.08 g/mol = 4.217 mol
One mole of calcium contains 6.022 x 10^23 atoms. Therefore:
Number of atoms in 169 g of calcium = 4.217 mol × 6.022 x 10^23 atoms/mol = 2.54 x 10^24 atoms
Hence, there are 2.54 x 10^24 atoms in 169 g of calcium.
