How many electrons are in 0.990 oz of pure gold

To you can solve your question, you need the following data:
Each gold atom has 79 electrons
0.990 Oz = 28.066 g
Au atomic weight: 197g/mol
1 mol = 6.022 atoms

1 mol > 197 g
X mol > 28.066 g = 0.14 mol

1 mol > 6.022 atoms
0.14 mol --> X            = 0.86 atoms

1 gold atom > 79 electrons
0.86 gold atoms --> X = 67.78 electrons

Then, 0.990 oz of pure gold have 67.78 electrons