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