Today is Thursday,October 16th, 2014

Pre-Class:When we were naming things like CO2 and HNO3 and SrF2, what were all the atoms in

those compounds actually doing?

Also, take a worksheet and a paper towel.

Stuff You Need:Paper TowelWorksheet

In This Lesson:Ionic and Metallic

Bonding(Lesson 3 of 4)

Today’s Agenda

• Ionic and Metallic Bonds– How ions and metals come together…– …and stay together. Awww…

• Australian Bonding Videos– Koalas not included.

• Where is this in my book?– P. 194 and following…

By the end of this lesson…

• You should be able to describe the nature of an ionic or metallic bond.

Introductory Video

• TED: George Zaidan and Charles Morton – How Atoms Bond

Bonding Overview

• Like with Periodic Table Trends, I have a handy way of organizing this information.– Bonding Overview

The Types of Bonding

• There are three types of bonds out there:• Ionic Bonds– Metal/Nonmetal – Electrons are transferred from one

atom to another.• Metallic Bonds– Metal/Metal – A mixture of metals with delocalized

electrons that flow through all atoms’ shells.• Covalent/Molecular Bonds– Nonmetal/Nonmetal (or metalloid) – Electrons are

shared/fought over between atoms.

Ionic Bonding Video

• Australian!

Ionic Bonds

• Cations and anions are formed.– Metals lose electrons to achieve the octet.– Nonmetals gain electrons to achieve the octet.

• Opposite charges attract one another, forming the bond.

• The resulting compound is neutral.

Ionic Compounds

• Crystalline solids at room temperature– Think table salt.

• High melting points– Takes a lot of heat/energy to melt them.

• Conduct electricity when melted or dissolved– Electric eels in seawater.

• Finish your Bonding Overview sheets for Ionic Bonding. Questions?

Dissociation

• In water, ionic compounds sometimes break up into the ions of which they’re composed.– This is a process called dissociation.

Dissociation

CaCl

Cl

Ca2+Cl-

Cl-

Bound ions in… …component ions out.

Metallic Bonding Video

• Aluminium!

Metallic Bonds

• In metallic bonds, all the cations are packed closely together.

• The valence electrons, rather than hanging out near their atoms’ nuclei, exist in a sea of delocalized electrons.– They float around everywhere and act as a glue, like mortar

around bricks in a building.• There is still an attraction between the free floating

electrons (-) and metal cations (+).

Metallic Compounds

• Good conductors of electricity– Think copper wiring.

• Ductile and malleable– Think copper wiring.

• Melting points vary• Insoluble in water

– Cause, well, metals just don’t dissolve.• Alloys

– Mixtures of two or more metals that have superior properties to their components.• Brass, bronze, steel are alloys.

• Finish your Bonding Overview sheets for Metallic Bonding. Questions?

Ionic Lewis Dot Structures

• In order to understand ionic compounds, it helps to be able to draw Lewis Dot Structures for ionic compounds.

• Let’s practice using an easy ionic compound – sodium chloride.

Ionic Lewis Dot Structures

• First, find the chemical formula for the compound.– Na likes to form 1+ ions, Cl likes to form 1- ions.– Na+ and Cl- balance together in a formula as NaCl.

• Then, draw the appropriate number of electrons in Lewis Dot form.

• Finally, “transfer” the electrons appropriately.

Na Cl

Ca

Ionic Lewis Dot Structures

• Example: Calcium oxide– CaO

O

Ionic Lewis Dot Structures

• Try this one: Aluminum nitride– AlN

Al N

Ionic Lewis Dot Structures

• Try this one: Magnesium sulfide– MgS

Mg S

Ionic Lewis Dot Structures

• Example: Iron (II) chloride– FeCl2

Fe Cl

Cl

Ionic Lewis Dot Structures

• Try this one: Cobalt (III) fluoride– CoF3

Co F

F

F

Ionic Lewis Dot Structures

• Try this one: Lithium oxide– Li2O

OLi

Li

Ionic Lewis Dot Structures

• Try this one: Silver phosphide– Ag3P

PAg

Ag Ag

Ionic Lewis Dot Structures

• Try this one: Barium nitride– Ba3N2

N BaBaBa

N

Ionic Lewis Dot Structures

• Try this one: Aluminum oxide– Al2O3

OAl

AlO

O

Ionic Lewis Dot Structures

• Try this one: Zinc iodide– ZnI2

Zn I

I

Practice

• Ionic Bonding Worksheet– Pages 1/2

Closure

• Try this one: Gold (III) sulfide– Au2S3