Ionic Bonds

How Bonds Form Electrons are transferred from a metal to a nonmetal. Ex: NaCl, CaI 2, Fe 2 O 3 -metals form cations (+) (gives away electrons) -non-metals form anions (–) (steals electrons)

Properties – Think SALT!! ALWAYS crystalline solid at room temperature VERY HIGH melting points and boiling points Hard and brittle Conduct electricity when melted or dissolved in water (ions – aqueous solution) Usually very soluble in water (dissolves)

Lewis Dot Structures Octet Rule: All atoms will form bonds in order to have full (8) valence electrons. 1.Draw a separate Lewis Dot structure for each element. 2.Draw arrows to show transfer of electrons. 3.If needed, add more atoms for transferring. Ex. Na and Cl Ex. Ca and F Used 1 Na +1 ion and 1 Cl -1 ion, so formula is NaCl. Used 1 Ca +2 ion and 2 F -1 ions, so formula is CaF 2. Example:Magnesium and Nitrogen

Naming 1.Write the name of the metal. (LEAVE SPACE HERE!) 2.Change the ending of the nonmetal to –ide. Ex 1. NaCl = Sodium chlorine = Sodium chloride Ex 2. Li 2 O = Lithium oxygen = Lithium oxide Ex 3. Mg 3 N 2 = Magnesium nitrogen = Magnesium nitride

Writing Chemical Formulas 1. Write the oxidation # (charge) of each ion above symbol. 2. If the charges cancel out, only 1 of each ion is needed. 3. If the charges for each atom do NOT cancel out, use the criss cross method to determine subscripts. 4. Write the formula using ONLY symbols and subscripts. Ex. Potassium phosphide K +1 P -3 K3PK3PK3PK3P

Writing Chemical Formulas (examples) Ex 1. Calcium sulfide Ca +2 S -2 CaS Fe +4 N -3 Ex 2. Iron ( IV) nitride Fe 3 N 4

Naming 1.Write the name of the metal. Use Roman numerals for transition metals to identify the charge. Check the charge of the nonmetal to help determine the transition metals charge. 2.Change the ending of the nonmetal to –ide. Ex 4. Cr 2 S 3 = Chromium sulfur = Chromium III sulfide Ex 5. CuO = Copper oxygen = Copper II oxide Ex 6. Cu 2 O = Copper oxygen = Copper I oxide

Naming (with polyatomic ions) 1.Write the name of the metal. Use Roman numerals for transition metals to identify the charge. Check the charge of the nonmetal to help determine the transition metals charge. OR ammonium 2.Change the ending of the nonmetal to –ide. OR name of polyatomic ion (do not change ending!)

Naming (examples) Ex 7. NH 4 Br = Ex 8. K 2 CO 3 = Ex 9. Ca(NO 3 ) 2 = Ex 10. Fe 3 (PO 4 ) 2 = ammonium bromide potassium carbonate calcium nitrate iron II phosphate -3 +2

Writing Chemical Formulas (examples) Ex 3. Sodium phosphate Na +1 ( PO 4 ) -3 Na 3 PO 4 Ex 4. Calcium nitrite Ca +2 ( NO 2 ) -1 Ca(NO 2 ) 2