Answer:
4.79 x10^24 atoms
Explanation:
55.2g/6.94g x (6.02 x 10^23) = 4.79 x10^24 Li atoms
First, you take the 55.2 g of Li and divide it by its molar mass. (Molar mass of Li is 6.94 g). Then you multiply it by Avogadro's number (6.02 x10^23) to get your answer.