Hello!
To find the mass of 7.602 x 10^24 atoms of lead, we need to find the number of moles first, then we will be able to find the mass. To find the moles, we need to divide the total number of atoms by Avogadro's number, which is 6.02 x 10^23. Also, one mole of lead is equal to it's atomic mass, which is 207.2 grams.
1). Find the number of moles
(7.602 x 10^24) / (6.02 x 10^23) ≈ 12.62790
Using significant figures, there are 12.8 moles of lead.
2). Find the mass of lead
12.8 moles x 207.2 grams = 2652.16 grams
Using significant figures, the mass of the given amount of lead is 2650 grams. (Exact value is 2652.16 grams).
