Indicate the oxidation number of phosphorus, iodine, nitrogen, tellurium, and sillicon in the following ions. Remember that the sum of the oxidation numbers for an ion must equal the charge of the ion.
a. PO43- b. PO33- c. HPO42-
d. P3O103- e. IO3- f. IO2-
g. IO- h. NH4+ i. NO2+
j. NO2- k. NO- l. NO3+
m. N2O22- n. TeO42- o. SiO22-