Answer
a. Bicarbonate is $HCO_3^-$
b. Ammonium is $NH_4^+$
c. Phosphite is $PO_3^{3-}$
d. Chlorate is $ClO_3^-$
Work Step by Step
You can find the answers to this question on page 197, table 6.7 'Names and Formulas of Some Common Polyatomic Ions'. Doing this, we find:
a. Bicarbonate is $HCO_3^-$
b. Ammonium is $NH_4^+$
c. Phosphite is $PO_3^{3-}$
d. Chlorate is $ClO_3^-$
