answer:
HNO₃= 5 atoms
SO₃= 4 atoms
NH₃= 4 atoms
2 Cl₂= 8 atoms
NaOH= 3 atoms
CaCO₃= 5 atoms
FeS₂= 3 atoms
KNO₃= 5 atoms
NaCl= 2 atoms
3 O₂= 6 atoms
K₂SO₄= 7 atoms
2 KOH= 2 atoms
KMnO₄= 6 atoms
CaCO₃= 5 atoms
4 CO₂= 12 atoms
C₂H₄O₂= 8 atoms
3 N₂O= 9 atoms
2 HNO₃= 10 atoms