Chapter 7Chapter 7Ionic and Metallic BondingIonic and Metallic Bonding
Mr. SamaniegoMr. Samaniego
Lawndale High SchoolLawndale High School
Section 7.1 - IonsSection 7.1 - Ions
• Valence Electrons – electrons in the highest occupied energy level of an atom
• To find the valence electrons in an atom of the representative element, simply look at the group number
•When Mendeleev arranged his periodic table according to properties, he didn’t know that it was also due to the number of bonding electrons
•The reason that certain elements were grouped together was because they have the same number of valence electrons
He 2 e-
Determine the Valence electrons Determine the Valence electrons in each of these elementsin each of these elements
1.1. KK 6. Be6. Be
2.2. PP 7. Li7. Li
3.3. CC 8. He8. He
4.4. OO 9. Ne9. Ne
5.5. NN 10. B10. B
Electron Dot Structure Electron Dot Structure A diagram that shows valence electrons A diagram that shows valence electrons
as dots around the element symbolas dots around the element symbol
PRACTICEPRACTICE
1. K1. K 6. Be6. Be
2. P2. P 7. Li7. Li
3. C3. C 8. He8. He
4. O4. O 9. Ne9. Ne
5. N5. N 10. B10. B
Valence ElectronsValence ElectronsThe reason that valence electrons are so The reason that valence electrons are so
important is that they are the only important is that they are the only electrons involved in bondingelectrons involved in bonding
Octet RuleOctet Rule
The Octet Rule states that all atoms The Octet Rule states that all atoms want 8 electrons in their valence want 8 electrons in their valence shellsshells, just like the noble gases , just like the noble gases (except He)(except He)
Remember that all atoms want to be like Remember that all atoms want to be like the noble gases because their s and p the noble gases because their s and p orbitals are completely filled, which orbitals are completely filled, which makes them unreactive and stablemakes them unreactive and stable
Satisfying the Octet RuleSatisfying the Octet Rule
In order for atoms to combine together to In order for atoms to combine together to obtain 8 valence electrons, they transfer obtain 8 valence electrons, they transfer electrons (either gain or lose electrons)electrons (either gain or lose electrons)
In forming compounds, atoms want to In forming compounds, atoms want to achieve a noble gas configurationachieve a noble gas configuration
Some atoms will gain electrons, Some atoms will gain electrons, while other atoms will lose electronswhile other atoms will lose electrons
Filling Order: 1s 2s 2p 3s 3p 4s 3d 4pFilling Order: 1s 2s 2p 3s 3p 4s 3d 4p
Draw the orbital diagram for SodiumDraw the orbital diagram for Sodium
Draw the orbital diagram for MagnesiumDraw the orbital diagram for Magnesium
Draw the orbital diagram for FluorineDraw the orbital diagram for Fluorine
Draw the orbital diagram for OxygenDraw the orbital diagram for Oxygen
Cation versus AnionCation versus AnionRemember that atoms are electrically Remember that atoms are electrically
neutral because they have the same neutral because they have the same number of protons and electronsnumber of protons and electrons
How are electrons transferred?How are electrons transferred?
Metals lose valence electronsMetals lose valence electrons
Nonmetals gain valence electronsNonmetals gain valence electrons
BondingBonding
Once an atom has a stable octet, it is Once an atom has a stable octet, it is happy and does not want to react anymorehappy and does not want to react anymore
Atoms without stable octets are Atoms without stable octets are sad and want to react with other sad and want to react with other atoms to achieve a stable octetatoms to achieve a stable octet
Why don’t noble gases want to form bonds?Why don’t noble gases want to form bonds?
Why do atoms form bonds?Why do atoms form bonds?1. To have a full octet1. To have a full octet2. To be more stable2. To be more stable
3. To be less reactive3. To be less reactive
How do atoms become more How do atoms become more stable and less reactive?stable and less reactive?
By having completely filled s and p By having completely filled s and p
orbitals just like the noble gases orbitals just like the noble gases
Charges on the Periodic TableCharges on the Periodic Table
PracticePractice What are the charges on the following elements?What are the charges on the following elements?
1.1. CalciumCalcium
2.2. OxygenOxygen
3.3. ChlorineChlorine
4.4. HydrogenHydrogen
5.5. CesiumCesium
6.6. HeliumHelium
7.7. KryptonKrypton
8.8. AluminumAluminum
Section 7.2 – Ionic BondsSection 7.2 – Ionic Bonds
Ionic Compounds are METAL cations and Ionic Compounds are METAL cations and NONMETAL anions held together by NONMETAL anions held together by electrostatic forceselectrostatic forces
Ionic compounds are formed through Ionic compounds are formed through transferring or exchanging electronstransferring or exchanging electrons
Example…Example…Sodium Chloride (Salt, NaCl) is an Sodium Chloride (Salt, NaCl) is an
example of an ionic compoundexample of an ionic compound
PracticePractice
Which of the following are ionic compounds?Which of the following are ionic compounds?1.1. LiClLiCl
2.2. NaSNaS
3.3. CC22HH44
4.4. MgBrMgBr22
5.5. HH22OO
6.6. SiCSiC
7.7. RbRb33PP
8.8. CsICsI
Ionic ChargesIonic ChargesAlthough they are composed of Although they are composed of
positive and negative charges, positive and negative charges, ionic compounds are overall ionic compounds are overall electrically neutral electrically neutral because their because their charges will cancel outcharges will cancel out
For example…For example…NaNa+1+1 will bond with Cl will bond with Cl-1-1
MgMg2+2+ will bond with O will bond with O2-2-
AlAl3+3+ will bond with N will bond with N3-3-
Two KTwo K+1+1 can also bond with One S can also bond with One S2-2-
Writing Chemical FormulasWriting Chemical Formulas
AlAl3+3+ SS2-2-
AlAl22SS33
AlAl3+3+ SS2-2-SS2-2-
The numbers on top are the charges, The numbers on top are the charges, while the numbers on the bottom tell while the numbers on the bottom tell
how many atoms there arehow many atoms there are
PracticePractice
Write as many compounds as you can Write as many compounds as you can with the following ions. Remember with the following ions. Remember
that the overall charge must be zero. that the overall charge must be zero. There are 9 possible.There are 9 possible.
Li+1 Ca2+ Al3+ N3- S2- Cl-1
SaltSalt
Salt crystals are repeating patterns of Salt crystals are repeating patterns of positive and negative ions held together by positive and negative ions held together by electrostatic attractionelectrostatic attraction
Ionic BondingIonic Bonding
When cations and anions transfer When cations and anions transfer electrons, a SALT is formedelectrons, a SALT is formed
Draw the electron dot structure for the Draw the electron dot structure for the following atomsfollowing atomsLi and BrLi and BrMg and OMg and OTwo K and One STwo K and One SOne Sr and Two FOne Sr and Two F
When cations and anions form bonds When cations and anions form bonds with each other they are called SALTSwith each other they are called SALTS
Example:Example:
Li Li 1s1s 2p2p
FF1s1s 2p2p
Li+
F-
LiF
SALTS
Practice Practice Show how the following compounds bond Show how the following compounds bond
with the use of orbital diagramswith the use of orbital diagrams
1.1. NaFNaF
2.2. MgOMgO
3.3. LiLi22SS
4.4. CaClCaCl22
5.5. AlNAlN
Properties of Ionic CompoundsProperties of Ionic CompoundsCrystallineCrystalline Solid at Room TemperatureSolid at Room TemperatureHigh Melting PointsHigh Melting PointsCan conduct an electric current when Can conduct an electric current when
melted or dissolved in watermelted or dissolved in water
Section 7.3 – Bonding in MetalsSection 7.3 – Bonding in Metals
Metal atoms are Metal atoms are arranged in very arranged in very compact and compact and orderly patternsorderly patterns
Metallic BondMetallic BondA Metallic Bond is a bond between metal A Metallic Bond is a bond between metal
cations surrounded by a sea of electronscations surrounded by a sea of electrons
Metallic BondMetallic Bond
The The attraction of attraction of the free the free floating floating valence valence electrons electrons holds them holds them togethertogether
Crystalline Structure of MetalsCrystalline Structure of Metals(Page 202)(Page 202)
Properties of MetalsProperties of Metals
1.1.Good Conductors of Good Conductors of electrical currentelectrical current
2. Ductile (ability 2. Ductile (ability to be stretched)to be stretched)
3. Malleable 3. Malleable (ability to be (ability to be shaped)shaped)
AlloysAlloys
Alloys are a mixture of two or more Alloys are a mixture of two or more elements, at least one being a metalelements, at least one being a metal
Very few of the metal objects you use Very few of the metal objects you use everyday are pure metalseveryday are pure metals
Alloys are important because the Alloys are important because the combination of metals are stronger combination of metals are stronger than the single metal by itselfthan the single metal by itself
Examples of Alloy CombinationsExamples of Alloy CombinationsBrass – copper and zincBrass – copper and zincSterling Silver – silver and copperSterling Silver – silver and copperBronze – copper and tinBronze – copper and tinSteel – iron, carbon, boron, chromium, Steel – iron, carbon, boron, chromium,
manganese, molybdenum, nickel, manganese, molybdenum, nickel, tungsten, vanadiumtungsten, vanadium
Stainless Steel – iron, chromium, carbon, Stainless Steel – iron, chromium, carbon, nickelnickel
Cast Iron – iron and carbonCast Iron – iron and carbon
HomeworkHomework
Chapter 7 AssessmentChapter 7 Assessment
#’s 30-44, 48, 53, 55, 56, 58, 59, 60, 62, 63, #’s 30-44, 48, 53, 55, 56, 58, 59, 60, 62, 63, 64, 65, 72, 73, 87, 88, 90, 92, 93, 94, 9564, 65, 72, 73, 87, 88, 90, 92, 93, 94, 95