1. Find the molar mass of lithium:
* The molar mass of lithium (Li) is approximately 6.941 g/mol.
2. Calculate the number of moles of lithium:
* Divide the given mass by the molar mass:
* Moles of Li = (18.7 g) / (6.941 g/mol) ≈ 2.69 mol
3. Use Avogadro's number:
* Avogadro's number states that there are 6.022 x 10^23 atoms in one mole of any substance.
* Multiply the number of moles by Avogadro's number:
* Atoms of Li = (2.69 mol) * (6.022 x 10^23 atoms/mol) ≈ 1.62 x 10^24 atoms
Therefore, there are approximately 1.62 x 10^24 atoms of lithium in 18.7 grams.
