The Basics of Ionic Chemical Bonding Unit 3: Types of Bonding The Basics of Ionic Chemical Bonding

Three types of bonding: Ionic Bonding: electrons are transferred (between a metal and non-metal) Covalent Bonding: electrons are shared (between a non-metal and non-metal) Metallic Bonding electrons flow freely (within a metal)

Introduction to Ionic Bonding An ionic bond forms from the attraction between + and – ions. An ionic compound is made up of crystals A crystal consists of a 3D, repeating pattern of alternating + and – ions.

Examples: The formation of ionic compounds Use electron dot structures to predict the compounds that would form between Sodium and Fluorine: To write the formula write the metal first, then the nonmetal… F Na NaF **Naming Ionic compounds: Metal Nonmetal (change the ending on the nonmetal to –ide) Name: Sodium Fluoride

Examples: The formation of ionic compounds Use electron dot structures to predict the compounds that would form between Magnesium and Chlorine: Cl Mg MgCl2 Cl **Naming Ionic compounds: Metal Nonmetal (change the ending on the nonmetal to –ide) Name: Magnesium Chloride

Examples: The formation of ionic compounds Use electron dot structures to predict the compounds that would form between Aluminum and Sulfur: Al S Al S Al2S3 S **Naming Ionic compounds: Metal Nonmetal (change the ending on the nonmetal to –ide) Name: Aluminum sulfide

Chemistry Humor 

Ions can be monatomic or polyatomic: Monatomic: Made up of a single atom Polyatomic: Made up of multiple atoms Remember… Group #: 1 2 13 14 15 16 17 18 Charge: +1 +2 +3 X -3 -2 -1 

Polyatomic ions: (See polyatomic ion sheet) are made up of two or more elements covalently bonded together with an overall positive or negative charge. *The six polyatomic ions that have asterisk with them have to be memorized.

Chemical Name to Formula Aluminum Sulfite Al+3 (SO3)-2 (SO3)-2 Al2(SO3)3

You can work backwards to determine the charge on transition metals! More Examples Silver Sulfate Ag? (SO4)-2 Ag+1 Ag2(SO4) Ag+1 You can work backwards to determine the charge on transition metals!

More Examples Calcium Bromide Ca+2 Br-1 Br-1 CaBr2

Parentheses () are optional when only one polyatomic ion is needed. More Examples Lithium Nitrate Li+1 (NO3)-1 LiNO3 Parentheses () are optional when only one polyatomic ion is needed.

But what if the metal is a transition metal? The Roman Numeral in the name represents the charge on the cation. Example: Nickel (II) Nitrate

More Examples Nickel (II) Nitrate Ni+2 (NO3)-1 (NO3)-1 Ni(NO3)2 The Roman Numeral will always tell you the charge and it will always be positive

More Examples Iron (III) Chloride Fe+3 Cl-1 Cl-1 FeCl3

Chemical Formula to Name Recall the format for chemical formulas… (name of cation – metal) (name of anion – nonmetal) Examples: KBr CaI2 Na2(SO4) Potassium Bromide Calcium Iodide Sodium Sulfate

For elements with more than one possible charge (transition metals)… Use the charge on the anion to determine the charge on the cation! Example: Fe2(CrO4)3 +6/2=+3 -2(3)=-6 Iron (III) Chromate

Example: Sn(CO3)2 +4 -2(2)=-4 Tin (IV) Carbonate

Example: Cu3P +3/3=+1 -3 Copper (I) Phosphide

Example: Co2(CrO4)3 +6/2=+3 -2(3)=-6 Cobalt (III) Chromate

Review of Ionic Compounds (Crystals) Transfer of electrons Made from a metal and a non-metal Metals lose electrons, nonmetals gain electrons Chemical formula is arranged in the smallest whole number ratio Even though ionic compounds are made up of ions, they ARE ELECTRICALLY NEUTRAL!