This is the list of ions and their symbols that are used in class so often you need to memorize them:
| aluminum | Al3+ | | acetate | CH3COO- | |
ammonium | NH4+ | | perchlorate | ClO4- | |
hydrogen | H+ | | chlorate | ClO3- | |
| Lithium | Li+ | | chlorite | ClO2- |
| potassium | K+ | | hypochlorite | ClO- |
| silver | Ag+ | | cyanide | CN- |
| sodium | Na+ | | hydroxide | OH- |
| barium | Ba2+ | | iodate | IO3- |
| cadimum | Cd2+ | | nitrate | NO3- |
| cobalt (II) | Co2+ | | nitrite | NO2- |
| cobalt (III) | Co3+ | | permanganate | MnO4- |
| copper(I) | Cu+ | | carbonate | CO32- |
| copper (II) | Cu2+ | | chromate | CrO42- |
| iron (II) | Fe2+ | | dichromate | Cr2O72- |
| iron (III) | Fe3+ | | oxalate | C2O42- |
| chromium (II) | Cr2+ | | peroxide | O22- |
| chromium (III) | Cr3+ | | silicate | SiO32+ |
| chromium (VI) | Cr6+ | | sulfate | SO42- |
| lead (II) | Pb2+ | | sulfite | SO32- |
| lead (IV) | Pb4+ | | thiosulfate | S2O32-2- |
| magnesium | Mg2+ | | phosphate | PO43- |
| mercury (I) | Hg22+ | | |
| mercury (II) | Hg2+ | | |
| nickel (II) | Ni2+ | | | |
| strontium | Sr2+ | | | |
| tin (II) | Sn2+ | | | |
| tin (IV) | Sn4+ | | | |
| zinc | Zn2+ | | | |