Which of the following are empirical formulas?(Could be as many as 3) 1. H2O2 2. H2SO4 3. S2Cl2 4. CH2O 5. N2 6. C2H4

Which of the following are empirical formulas?(Could be as many as 3)
1. H2O2 
2. H2SO4 
3. S2Cl2 
4. CH2O 
5. N2 
6. C2H4

H2O2 = 2(HO) = HO

H2SO4

S2Cl2 = 2(SCl) = SCl

CH2O

N2 = 2N = N

C2H4 = 2(CH2) = CH2