3 Tutor System
Starting just at 265/hour

# How many atoms are present in a (i) H$$_2$$S molecule and (ii) PO$$_4$$$$^{3-}$$ ion?

(i) H$$_2$$S molecule has 2 atoms of hydrogen and 1 atom of sulphur hence H$$_2$$S molecule a total of 3 atoms.
(ii) PO$$_4$$$$^{3-}$$ ion has 1 atom of phosphorus and 4 atoms of oxygen hence PO$$_4$$$$^{3-}$$ ion has a total of 5 atoms.