Determine the mass in grams of 6.65 x 10^21 atoms of barium

Answer 1

First we convert number of atoms to moles in the roadmap, then from moles to grams of Barium

6.65X10^21 atoms X (1 mol / 6.022X10^23 atoms)(137.3 g Ba / 1 mol Ba) = 1.52 g Barium