4

1. 4.11 g O atoms

2. 0.0032 kg O2 = 3.2 g

3. (2.38 × 10^23 O2 molecules) / (6.022 x 10^23 molecules/mol) x (31.99886 g O2/mol) = 12.6 g

4. 3.83 mol O atoms x (15.99943 g O/mol) = 61.3 g

So answer 4.