Oxidation numbers

1

What is the oxidation state of each element in the following:

 2

Write down the oxidation state of N in the following:

 3

Write down the oxidation state of each element in red:

 4

Use oxidation numbers to work out the formula of the following ions
  a K 0   a N2O +1 a NaClO3 +5 a Chlorate (III) with an overall charge of 1- ClO2-
  b Br2 0   b N2O5 +5 b Na2SO3 +4 b Chlorate (VII) with an overall charge of 1- ClO4-
  c NH4+ -3 +1 c N2H4 -2 c KMnO4 +7 c Phosphate (III) with an overall charge of 3- PO33-
  d CaF2 +2 -1 d NO3- +5 d K2MnO4 +6 d Chromate (VI) with an overall charge of 2- CrO42-
  e Al2O3 +3 -2 e HNO2 +3 e K2Cr2O7 +6      
  f NO3- +5 -2                  
  g PO43- +5 -2