What are the oxidation numbers for each element in these compounds and ions?

[yuuri14]

Determine the oxidation number for each atoms in the following compounds or ions:
a) H3 0+
ox # -2
b)P4 O10
ox #-3
c)S8
ox #5
d)H2 CO
ox #4
e)NH4 CLO4
ox #2
I need help to know if i am doing it right.

 

[PhaseShifter]

Each type of atom in each compound will have a different oxidation number...so for a you have different answers for oxygen and hydrogen, for b you have different oxidation numbers for phosphorous and oxygen, d has 3 elements, etc...

 

[yuuri14]

Thanks 4 the help. I know that I need to just tell the ox. #s +/- of each the elements.

 

[Borek]

So you can't give ONE answer to each question.

e has four elements - oxidation number 2 refers to H, N, O or Cl?