Here are the formulas for the combinations of the ions and polyatomic ions you provided:
a) Na+ and CO32- form sodium carbonate: Na2CO3
b) Na+ and HC031- form sodium bicarbonate or sodium hydrogen carbonate: NaHCO3
c) Na+ and NO21- do not typically form a stable compound. It seems there might be a typographical error as "NO21-" is not a recognized polyatomic ion.
d) Na+ and NO31- do not typically form a stable compound. "NO31-" is not a recognized polyatomic ion.
e) Na+ and SO42- form sodium sulfate: Na2SO4
f) Na+ and SO32- form sodium sulfite: Na2SO3
g) Na+ and PO43- form sodium phosphate: Na3PO4
Please note that while these are the commonly known combinations, the actual formation of compounds depends on specific reaction conditions and other factors.