1. Intro to Names and Formulas for Ionic Compounds November 2, 2015

2. Chemical Formula Octane: C 8 H 18 In 1 molecule of octane there are 8 carbon atoms (C) and 18 hydrogen atoms (H). Aluminum Sulfate: Al 2 (SO 4 ) 3 In 1 molecule of aluminum sulfate there are 2 aluminum atoms (Al), 3 sulfur atoms (S), and 12 oxygen (O) atoms.

3. Ions All atoms want a full outer shell of electrons (8 valence electrons) Atoms will lose or gain electrons in order to have a full outer shell Atoms that lose electrons are cations Atoms that gain electrons are anions

4. Monatomic Ions Group #1 elements form +1 ions, Ex) Li +, Na +1 Group #2 elements form +2 ions, Ex) Ca +2, Mg 2+ Aluminum forms +3 ions Nitrogen and phosphorus form -3 ions Oxygen and sulfur form -2 ions The halogens, F, Cl, Br, I, form -1 ions Transition metals can form multiple ions: Ex) Fe +3 and Fe +2

5. Naming Monatomic Ions Cations are identified by element’s name Ex) Li + lithium Ex) Ca +2 calcium Anions-ending of element’s name is replaced by ide Ex) F - fluoride Ex) O -2 oxide

6. Writing Names and Formulas for Ionic Compounds (Ionic =metal and nonmetal) Ex 1) Aluminum and Oxygen Ex 2) Magnesium and Bromine Ex 3) Copper and Bromine (Copper has +2 charge) Ex 4) Chromium and Fluorine (Chromium has +3 charge)

7. Compounds with Polyatomic Ions See table on p 226 (I will give you a list of polyatomic ions you need to memorize) Ex 1) Calcium and Hydroxide (Hydroxide is polyatomic ion: OH - ) Name: calcium hydroxide Formula Ca(OH) 2

8. Practice Write the names of the following compounds: 1) CaCl 2 2) BaO 2 3) KCl 4) K 2 O