BRN: What do you see?

Bonding New section in table of contents

Properties Review What if we just look at the compounds that conducted electricity CompoundConductivity Tap water (H 2 O)Yes Sodium Chloride (NaCl)Yes Hydrochloric Acid (HCl)Yes Lithium Fluoride (LiF)Yes What do these compounds have in common?

What is an ionic compound?  How would you define a salt?  A salt is just an ionic compound  So what is an ionic compound?  KC 1: An ionic compound consists of a metal and a non-metal bound together in a lattice structure by ionic bonds  How would you define a salt?  A salt is just an ionic compound  So what is an ionic compound?  KC 1: An ionic compound consists of a metal and a non-metal bound together in a lattice structure by ionic bonds

Ionic Compounds  KC2: Ionic Compound = metal + nonmetal or cation + anion  KC2: Ionic Compound = metal + nonmetal or cation + anion

Ionic Compounds  KC 3: Cation – positively charged ion  KC 4: Anion – negatively charged ion  Polyatomic Ions  “Poly” = many  “atomic” = atoms  Ion = charged  KC 5: Polyatmoic ion = many atoms bonded together having an overall charge  See periodic table  KC 3: Cation – positively charged ion  KC 4: Anion – negatively charged ion  Polyatomic Ions  “Poly” = many  “atomic” = atoms  Ion = charged  KC 5: Polyatmoic ion = many atoms bonded together having an overall charge  See periodic table

Ionic Bonding  KC 6: Ionic Bond – bond formed through electrostatic attraction between 2 oppositely charged ions  Review: What is an ion?  Different number of electrons from protons  Not a neutral atom  Contains a charge  KC 6: Ionic Bond – bond formed through electrostatic attraction between 2 oppositely charged ions  Review: What is an ion?  Different number of electrons from protons  Not a neutral atom  Contains a charge

dissociation animation

8 is the magic number! KC 7: All atoms are trying to reach a valence shell of 8 – like a noble gas KC 8: If this cannot be achieved easily, an atom will lose electrons to have a valence shell of zero

Ionic Bonding  Each atom forms a charge that is related to its number of valence electrons  Example: calcium – 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2  2 valence electrons  8 is the magic number!  Is it easier to gain 6 or lose 2?  Each atom forms a charge that is related to its number of valence electrons  Example: calcium – 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2  2 valence electrons  8 is the magic number!  Is it easier to gain 6 or lose 2?

Ionic Bonding – Ions worksheet ElementMetal/Nonmetal # Valence Electrons # Electrons to gain # Electrons to lose Ion Formed/name LiMetal1None1Li 1+ / cation NNonmetal53NoneN 3- / anion

Ionic Bonding

Naming Rules – formula to name  There are 3 different “types” of naming rules for ionic compounds based on what metals and nonmetals are involved  Type A: metal + nonmetal  NaCl  Type B: metal + anion (polyatomic ions)  CaCO 3  Type C: transition metal + nonmetal  CuCl  There are 3 different “types” of naming rules for ionic compounds based on what metals and nonmetals are involved  Type A: metal + nonmetal  NaCl  Type B: metal + anion (polyatomic ions)  CaCO 3  Type C: transition metal + nonmetal  CuCl

KC 9: Type A  Metal + Nonmetal 1.Name the metal 2.Name the nonmetal 3.Change the ending of the nonmetal to “ide” Example: NaCl – sodium chloride  Metal + Nonmetal 1.Name the metal 2.Name the nonmetal 3.Change the ending of the nonmetal to “ide” Example: NaCl – sodium chloride

KC 10: Type B  Metal + Anion 1.Name the metal 2.Name the anion, but if it is a polyatomic ion, DO NOT change the ending Example: CaCO 3 – calcium carbonate  Metal + Anion 1.Name the metal 2.Name the anion, but if it is a polyatomic ion, DO NOT change the ending Example: CaCO 3 – calcium carbonate

EXCEPTION ALERT!!  There is 1 polyatomic ion that is a cation, which means it is NOT a metal  NH ammonium  Example: NH 4 NO 3 – ammonium nitrate  There is 1 polyatomic ion that is a cation, which means it is NOT a metal  NH ammonium  Example: NH 4 NO 3 – ammonium nitrate

KC 11: Type C  Transition Metal + nonmetal 1.Name the transition metal 2.Figure out the charge of the transition metal and place in Roman numerals in parenthesis 3.Name the nonmetal:  If it is a regular nonmetal – change the ending to “ide”  If it is a polyatomic ion – DO NOT change the ending Example: CuCl – copper (I) chloride  Transition Metal + nonmetal 1.Name the transition metal 2.Figure out the charge of the transition metal and place in Roman numerals in parenthesis 3.Name the nonmetal:  If it is a regular nonmetal – change the ending to “ide”  If it is a polyatomic ion – DO NOT change the ending Example: CuCl – copper (I) chloride

Creating Ionic Compounds – the switcheroo!  KC 12: When bonding a metal and nonmetal in an ionic compound, the charges have to balance  To do this, you just switch the charges and cross them down: the switcheroo  Can also be done the opposite way to determine charges  KC 12: When bonding a metal and nonmetal in an ionic compound, the charges have to balance  To do this, you just switch the charges and cross them down: the switcheroo  Can also be done the opposite way to determine charges

The Switcheroo!  Example: aluminum chloride

EXCEPTION ALERT!!  What if you do the switcheroo and the charge for a nonmetal does not come out correctly?  Example – CuO  What if you do the switcheroo and the charge for a nonmetal does not come out correctly?  Example – CuO

EXCEPTION ALERT!!  If the charge of the nonmetal comes out wrong, that means the charges have reduced  To correct the charge, just multiply both charges by the necessary number to make it the charge that you know it is  Example - CuO  If the charge of the nonmetal comes out wrong, that means the charges have reduced  To correct the charge, just multiply both charges by the necessary number to make it the charge that you know it is  Example - CuO

Naming Rules - practice  Practice determining the charges for the transition metals in the following compounds  CrO  CuCl 2  MnO 2  Practice determining the charges for the transition metals in the following compounds  CrO  CuCl 2  MnO 2

KC 13: Name to Formula 1.Write the ion symbol for the cation and anion with correct charge* 2.Do the switcheroo to balance the charges For Transition Metals: *the roman numeral in the name gives you the charge* 1.Write the ion symbol for the cation and anion with correct charge* 2.Do the switcheroo to balance the charges For Transition Metals: *the roman numeral in the name gives you the charge*

Naming Rules – name to formula Example: copper (II) chloride

Naming Rules  From your notes, create a tree map of how to name ionic compounds  There are 3 different types of ionic compounds  Metal + nonmetal  Transition metal + nonmetal  Metal + polyatomic ion  From your notes, create a tree map of how to name ionic compounds  There are 3 different types of ionic compounds  Metal + nonmetal  Transition metal + nonmetal  Metal + polyatomic ion

Naming Ionic Compounds – formula to name Type A: Metal + Nonmetal Name the metal Name the nonmetal Change the nonmetal ending to “ide” Type B: Metal + Polyatomic Ion Name the metal Name the polyatomic ion Type C: Transition Metal + Nonmetal Name the transition metal Find the charge of the metal and place in roman numerals Name the nonmetal

Covalent Compounds & Bonding  KC 14: Covalent compounds consist of 2 or more nonmetals bonded together  KC 15: A covalent bond is formed from the sharing of electrons  KC 14: Covalent compounds consist of 2 or more nonmetals bonded together  KC 15: A covalent bond is formed from the sharing of electrons

Ionic Bondvs.Covalent Bond

KC 16: Naming Covalent Compounds  The rules for molecular compounds are much easier than ionic (no exceptions…woot!) 1.Write the Greek prefix for the first element 2.Write the name for the first element 3.Write the Greek prefix for the second element 4.Write the name for the second element Example: N 2 O 5 – dinitrogen pentoxide  The rules for molecular compounds are much easier than ionic (no exceptions…woot!) 1.Write the Greek prefix for the first element 2.Write the name for the first element 3.Write the Greek prefix for the second element 4.Write the name for the second element Example: N 2 O 5 – dinitrogen pentoxide

Naming Covalent Compounds  KC 17: Greek Prefixes 1 = mono 2 = di 3 = tri 4 = tetra 5 = penta 6 = hexa 7 = hepta 8 = octa 9 = nano 10 = deca  KC 17: Greek Prefixes 1 = mono 2 = di 3 = tri 4 = tetra 5 = penta 6 = hexa 7 = hepta 8 = octa 9 = nano 10 = deca

Naming Covalent Compounds  Going from name to formula, you just write the element symbol with the subscript that matches the prefix from the name Example: triphosphorus hexafluoride – P 3 F 5  Going from name to formula, you just write the element symbol with the subscript that matches the prefix from the name Example: triphosphorus hexafluoride – P 3 F 5

Naming Covalent Compounds  Create a tree map or flow diagram explaining how to name covalent compounds

Covalent Compounds -formula to name Write the Greek prefix for the first element and name it 1 = mono6 = hexa 2 = di7 = hepta 3 = tri8 = octa 4 = tetra9 = nano 5 = penta10 = deca Write the prefix for the second element and name it

Bonding  KC 18: Some molecules are more stable when they are found as diatomic – two of the same element covalently bonded BrINClHOF

Bonding

KC 19: Lewis Structure Rules 1.Draw skeleton of molecule or compound and count total valence electrons able to use 2.Give all elements full octet and a single bond between elements. 3.Count number of electrons in drawing from step #2 and compare to number of electrons allowed 4.If too many, do the “move a pair lose a pair” rule until you have the correct number of electrons  Move electrons from outside in to form double or triple bond then erase a pair of electrons from the outside 1.Draw skeleton of molecule or compound and count total valence electrons able to use 2.Give all elements full octet and a single bond between elements. 3.Count number of electrons in drawing from step #2 and compare to number of electrons allowed 4.If too many, do the “move a pair lose a pair” rule until you have the correct number of electrons  Move electrons from outside in to form double or triple bond then erase a pair of electrons from the outside

 How many electrons does hydrogen have?  Will it be happy with 8?  NO!  KC 20: Hydrogen follows the duet rule – only needs 2 electrons to be happy  How many electrons does hydrogen have?  Will it be happy with 8?  NO!  KC 20: Hydrogen follows the duet rule – only needs 2 electrons to be happy EXCEPTION ALERT!!

Lewis Structure Rules 1.Draw skeleton of molecule or compound and count total number of valence electrons to use  Follows logic; place the element that is only contained once in the middle Example: CO 2 C = 4e - O = 6 x 2 = 12e - Total = 16e - 1.Draw skeleton of molecule or compound and count total number of valence electrons to use  Follows logic; place the element that is only contained once in the middle Example: CO 2 C = 4e - O = 6 x 2 = 12e - Total = 16e -

Lewis Structure Rules 2.Give all elements full octet (8 around each element) and a single bond between elements. Example: CO 2 16e - 2.Give all elements full octet (8 around each element) and a single bond between elements. Example: CO 2 16e -

Lewis Structure Rules 3. Count number of electrons in drawing from step #2 and compare to number of electrons allowed Example: CO 2 3. Count number of electrons in drawing from step #2 and compare to number of electrons allowed Example: CO 2

Lewis Structure Rules 4. If too many, do the move a pair lose a pair rule until you have the correct number of electrons  Move electrons from outside in to form double or triple bond then erase a pair of electrons from the outside Example: CO 2 **Cannot break octet rule!!** 4. If too many, do the move a pair lose a pair rule until you have the correct number of electrons  Move electrons from outside in to form double or triple bond then erase a pair of electrons from the outside Example: CO 2 **Cannot break octet rule!!**

Lewis Structure Rules  Most Lewis structures for compounds follow the common bonding patterns: 4 bonds3 bonds2 bonds1 bond 0 L.P.1 L.P.2 L.P.3L.P.  Most Lewis structures for compounds follow the common bonding patterns: 4 bonds3 bonds2 bonds1 bond 0 L.P.1 L.P.2 L.P.3L.P.

Bonds: Lone Pairs:

Lewis Structure Practice  On your white boards, draw the Lewis structure for the following molecules:  CO 2  H 2 O  CH 4  CF 2 Cl 2  On your white boards, draw the Lewis structure for the following molecules:  CO 2  H 2 O  CH 4  CF 2 Cl 2

Shapes of Molecules  The Lewis structure can be transferred into a 3D model that tells us the exact shape, bond angles, and polarity of molecules

# of things # bonds # lone pairs Molecular geometry Bond angle Example 2 20linear180CO Trigonal planar 120BF 3 321Bent<120SO 2 440tetrahedral<109.5CH Trigonal pyramidal <109.5NH 3 422Bent<109.5H2OH2O

Polarity  KC 21: The shape of the molecule and the electronegativity of the elements determines the molecule’s polarity  We use vectors to represent polarity  Demonstration: H 2 O  KC 21: The shape of the molecule and the electronegativity of the elements determines the molecule’s polarity  We use vectors to represent polarity  Demonstration: H 2 O

Your turn!  You are going to be given a molecule to build and show to the class  You must include:  Name  Formula  Lewis structure  Molecular geometry  polarity  You are going to be given a molecule to build and show to the class  You must include:  Name  Formula  Lewis structure  Molecular geometry  polarity