Question

what is the name of the ions that are formed when the following compounds dissolve in water. (a) BaBr2 (b) (NH4)2CrO4 (c)HBr

Answer 1

The + ion is simply the name of the metal; e.g. NaCl is sodium ion for the Na^+. For binary compounds (two elements to the compound such as NaCl), the anion takes the stem from the element. Cl is chlor-and add ide. Cl^- is chloride. Br^- is bromide, I^- iodide, etc. Here is a table for polyatomic ions. If you intend to take more than one course in chemistry you should memorize this chart.
http://www.woodrow.org/teachers/chemistry/links/chem1/PolyatomicIonsChart.html