Ionic CompoundsIonic Compounds

What’s a chemical bond?What’s a chemical bond?

A chemical bond is the A chemical bond is the force that holds force that holds two atoms togethertwo atoms together

Two types of chemical bonds:Two types of chemical bonds:– Ionic Ionic – CovalentCovalent

Why do atoms form bonds?Why do atoms form bonds?

Formation of Formation of chemical bonds is chemical bonds is due to number of due to number of valence electronsvalence electrons

Why do valence Why do valence electrons play such electrons play such an important role?an important role?

How many electrons do atoms want to have in their outermost energy level?

– Because Because elements reactelements react to to get the stable get the stable electron structure electron structure of a noble gasof a noble gas

8

The Octet RuleThe Octet Rule

States that atomsStates that atoms lose, gain or share lose, gain or share electrons in order electrons in order to acquire a full set to acquire a full set of eight valence of eight valence electronselectrons

Why? This is the Why? This is the stable electron stable electron configuration of the configuration of the noble gasesnoble gases

How do we know if they will gain or lose electrons?

Atoms will do what is easiest to get the most stable electron configuration.

Atoms with 5, 6 or 7 valence electrons will ___________ electrons.

Atoms with 1, 2 or 3 valence electrons will ___________ electrons.lose

gain

How do atoms form bonds?How do atoms form bonds?

One way is by the formation of ions.One way is by the formation of ions. An ion is An ion is an atom an atom (or a group of bonded (or a group of bonded

atoms) withatoms) with aa positive or negative positive or negative chargecharge..

- Proton

- Neutron

- Electron

Sodium Atom

What would be the easiest way this sodium atom could get the perfect 8?

Sodium Ion

Positive or Negative Ion?Positive or Negative Ion?

How can you tell if the ion formed will be How can you tell if the ion formed will be positive or negative?positive or negative?– Count the protons and electronsCount the protons and electrons

How many protons? ___

How many electrons? ___

What’s the charge? ___

11

110

How many protons? ___

How many electrons? ___

What’s the charge? ___

11

10+1

Activity TimeActivity Time

Obtain an ion card from teacherObtain an ion card from teacher If you have a metal ion, go to the If you have a metal ion, go to the

back of the roomback of the room If you have a nonmetal ion, go to the If you have a nonmetal ion, go to the

front of the roomfront of the room Once there, look at the other Once there, look at the other

members of your group and start members of your group and start generating conclusionsgenerating conclusions

Conclusions from ActivityConclusions from Activity

What type of atoms form positive ions?What type of atoms form positive ions?– MetalsMetals

What type of atoms form negative ions?What type of atoms form negative ions?– NonmetalsNonmetals

Let’s Go FurtherLet’s Go Further

If you have an alkali metal, stand If you have an alkali metal, stand near the fire extinguishernear the fire extinguisher

If you have an alkaline earth metal, If you have an alkaline earth metal, stand by the fume hoodstand by the fume hood

If you have a transition metal, go to If you have a transition metal, go to the front middle lab tablethe front middle lab table

If you have a halogen, stand near the If you have a halogen, stand near the computercomputer

Any others? Stand by my deskAny others? Stand by my desk

What did we learn?What did we learn?

All alkali metals have a charge of _____.All alkali metals have a charge of _____. All alkaline earth metals have a charge of All alkaline earth metals have a charge of

_____._____. All halogens have a charge of ____.All halogens have a charge of ____. Group 6A elements have a charge of ____.Group 6A elements have a charge of ____.

+1 +

2-1

-2

Transition ElementsTransition Elements How many valence How many valence

electrons do transition electrons do transition elements have?elements have?– TwoTwo

They will commonly They will commonly lose those two valence lose those two valence electrons to form ions electrons to form ions with a with a +2+2 charge charge

But….they can also But….they can also lose some of their d lose some of their d electrons to form ions electrons to form ions of of +3+3, , +4+4 or greater or greater

Roman NumeralsRoman Numerals

System used to indicate numbersSystem used to indicate numbers– I = I = 11– II = II = 22– III = III = 33– IV = IV = 44

We use Roman Numerals to We use Roman Numerals to indicate indicate charge of transition metalscharge of transition metals– Copper (II) = Copper (II) = Copper +2Copper +2– Iron (III) = Iron (III) = Iron +3Iron +3

Names of IonsNames of Ions

A positively charged ion A positively charged ion is called a is called a cationcation..– A cation’s name is the A cation’s name is the

same as the elementsame as the element A negatively charge ion A negatively charge ion

is called an is called an anionanion..– An anion’s name has the An anion’s name has the

ending “ending “–ide–ide” added to ” added to the root namethe root name Example: Anion of chlorine Example: Anion of chlorine

is the chloride ion.is the chloride ion.

1. What is the oxygen ion called?

2. What is the fluorine ion called?

3. What is the bromine ion called?

oxide

fluoride

bromide

Practice QuestionsPractice Questions

1.1. Which type of atoms form cations?Which type of atoms form cations?

2.2. Which type of atoms form anions?Which type of atoms form anions?

3.3. Is NaIs Na++ a cation or anion? a cation or anion?

4.4. Is FIs F-- a cation of anion? a cation of anion?

5.5. Is CaIs Ca2+2+ a cation or anion? a cation or anion?

6.6. Is MgIs Mg2+2+ a cation or anion? a cation or anion?

7.7. What is the charge of the iodine ion?What is the charge of the iodine ion?

8.8. What is the name of the iodine anion?What is the name of the iodine anion?

9.9. Would oxygen form a cation or anion?Would oxygen form a cation or anion?

10.10. What is the net charge of zinc (II)?What is the net charge of zinc (II)?

metalsnonmetalscation

anion

cation

cation

-1

iodide

anion

2+

Monatomic vs. PolyatomicMonatomic vs. Polyatomic

Mono means oneMono means one Poly means manyPoly means many So, a monatomic So, a monatomic

ion refers to ion refers to ions ions with single atomswith single atoms

A polyatomic ion A polyatomic ion refers to refers to ions with ions with more than one more than one atomatom

Monatomic IonsMonatomic Ions

Elements as they are on the periodic Elements as they are on the periodic table form monatomic ionstable form monatomic ions

Polyatomic IonsPolyatomic Ions

Sulfate

Carbonate

Formed when more than one atom are grouped together

Charge on polyatomic ions applies to entire group of atoms.

The polyatomic ion acts as an individual ion

NHNH44++ AmmoniumAmmonium

NONO33-- NitrateNitrate

OHOH-- HydroxideHydroxide

COCO332-2- CarbonateCarbonate

SOSO442-2- SulfateSulfate

POPO443-3- PhosphatePhosphate

NONO22-- NitriteNitrite

Common Polyatomic Ions