2 Anatomy of a Chemical Formula Al2SO4Numbers at the bottom are called subscripts.They tell how many atoms of one type are in a compound.Ca+2Numbers at the top are called superscripts.They tell you the charge of the atom.
3 Polyatomic Ions CO3-2 carbon = 1 oxygen = 3 overall charge = -2 Group of atoms that have an overall charge. You will find both subscripts and superscripts in polyatomic ions.CO3-2 carbon = 1oxygen = 3overall charge = -2
4 3 Categories of Compounds IonicAcids & BasesMolecular
5 1) Ionic Compounds Contain IONIC bonds. Formed between metals and non-metals.Ions combine in small, whole number ratios.The sum of oxidation numbers will be zero! (they are neutral)
6 Binary Ionic Compounds All contain two elements.All end in “ide”.
7 Binary Ionic Compounds To write formula:1) Write + and - ions.2) Reduce oxidation numbers, if possible.3) “Criss-Cross” number only to become subscript for other ion.