# Naming Compounds Essay

759 WordsMay 12, 20124 Pages
Naming Compounds More Practice With Naming Before naming a compound, you have to figure out what kind of compound it is. We will consider three types: 1. Ionic Compounds Without a Transition Metal. Ionic compounds are formed when a metal gives up its electrons to a non-metal. Basically if the compound contains a metal, it is ionic. But there are different sets of rules for transition metals. A transition metal is an element with an atomic number of 21 to 30, 39 to 48 or 57 to 80. a. So for a compound with any other metal, apply these rules: * The metal ion's name does not change regardless of charge * The non-metal's name ends in ide. For example: AlCl3 = aluminum chloride Na2S = sodium sulfide K2O = potassium oxide MgH2 = magnesium hydride Notice how the little numbers (subscripts) do not affect the way we name them. b. In going backwards (from name to formula), we will have more fun. In such a case the total charge of the (+) and (-) ions in the compound has to be ZERO. Example: What is the correct formula for calcium phosphide? Here, we have to consider the common charges for calcium and phosphorus, which are +2 and -3, respectively. Calcium, if you recall, typically loses two electrons to get a noble gas electron arrangement, and phosphorus needs three more electrons. Ca+2 and P-3 One of each would create a sum of 2 + (-3) = -1. To get a sum of zero, we need three Ca+2 ions and two P-3 for a total of 3(2)+ 2(-3) = 0. So the answer is Ca3P2. Other examples: potassium oxide : K+1 and O-2 give K2O aluminum bromide Al+3 and Br-1 yield AlBr3.