• OBJECTIVES: –Determine the number of  valence electrons in an atom  of a representative element. –Explain how the octet ...
• OBJECTIVES: –Describe how cations form. –Explain how anions form. –Explain the electrical charge of  an ionic compound.
• OBJECTIVES: –Describe how cations form. –Explain how anions form. –Explain the electrical charge of  an ionic compound.
• OBJECTIVES: –Explain the electrical charge of  an ionic compound. –Describe three properties of  ionic compounds.
• OBJECTIVES: –Describe the arrangement of  atoms in a metal. –Explain the importance of  alloys.
The Octet RuleWe learned that noble gases are unreactive inchemical reactionsIn 1916, Gilbert Lewis used this fact toexpla...
Formation of Cations• Metals lose electrons to attain a noble gas  configuration.• They make positive ions (cations)
Electron Dots For Cations• Metals will have few valence electrons  (usually 3 or less); calcium has only 2  valence electr...
Electron Dots For Cations• Metals will have few valence electrons• Metals will lose the valence electrons  Ca
Electron Dots For Cations• Metals will have few valence electrons• Metals will lose the valence electrons• Forming positiv...
Electron Configurations: Anions• Nonmetals gain electrons to attain noble  gas configuration.• They make negative ions (an...
Electron Dots For Anions• Nonmetals will have many valence electrons  (usually 5 or more)• They will gain electrons to fil...
Stable Electron Configurations• All atoms react to try and achieve a noble  gas configuration.• 8 valence electrons = alre...
Octet Rule = atoms tend to gain, lose or share electrons soas to have 8 electrons       C would like to Gain 4 electrons ...
Learning Check      A.   X would be the electron dot formula for     1) Na           2) K             3) Al      B.   ...
Chemical bonds: an attempt to fill electron shells    1. Ionic bonds –    2. Covalent bonds –    3. Metallic bonds
IONIC BONDbond formed between   two ions by the transfer of electrons
Ionic Bonding —           Ionic Compounds• Anions and cations are held together by  opposite charges (+ and -)• Ionic comp...
Ionic Bonding      Na ClThe metal (sodium) tends to lose its oneelectron from the outer level.The nonmetal (chlorine) need...
Ionic Bonding  Na Cl+          -Note: Remember that NO DOTSare now shown for the cation!
Ionic BondingLets do an example by combiningcalcium and phosphorus:    Ca                        P• All the electrons must...
Ionic BondingCa              P
Ionic BondingCa   2+                     P
Ionic BondingCa   2+                     PCa
Ionic Bonding                          3-Ca   2+                     PCa
Ionic Bonding                          3-Ca   2+                     PCa                  P
Ionic Bonding                          3-Ca   2+                     PCa   2+                    P
Ionic BondingCa                        3-Ca 2+                   PCa   2+                  P
Ionic BondingCa                        3-Ca 2+                   PCa   2+                  P
Ionic BondingCa   2+                        3-Ca 2+                   PCa   2+                  P                        3-
Ionic Bonding = Ca3P2                   Formula UnitThis is a chemical formula, whichshows the kinds and numbers of atoms ...
Properties of Ionic Compounds1. Crystalline solids - a regular repeating   arrangement of ions in the solid: Fig. 5,   pag...
- Page 162       Coordination Numbers:           Both the sodiumNaCl       and chlorine have 6            Both the cesiumC...
Do they Conduct?•  Conducting electricity means allowing   charges to move.• In a solid, the ions are locked in place.• Io...
Formation of Ions from MetalsIonic compounds result when metals react with nonmetalsMetals lose electrons to match the n...
Formation of Sodium IonSodium atom            Sodium ion Na •     – e−   →     Na +2-8-1              2-8 ( = Ne)  11 p+...
Formation of Magnesium IonMagnesium atom        Magnesium ion• Mg •         – 2e−   →      Mg2+2-8-2                     ...
Some Typical Ions with Positive            Charges (Cations)Group 1        Group 2     Group 13H+             Mg2+        ...
Learning CheckA. Number of valence electrons in aluminum    1) 1 e-         2) 2 e-          3) 3 e-B.   Change in electro...
SolutionA. Number of valence electrons in aluminum    3)  3 e-B.   Change in electrons for octet      1)  lose 3e-C.    Io...
Learning CheckGive the ionic charge for each of the following:A. 12 p+ and 10 e-   1) 0        2) 2+       3) 2-B. 50p+ an...
Ions from Nonmetal IonsIn ionic compounds, nonmetals in 5A, 6A, and  7A gain electrons from metalsNonmetals add electron...
Fluoride Ion      unpaired electron   octet ••                          ••   1-:F•            + e−               : F: ••  ...
Ionic Bond• Between atoms of metals and nonmetals  with very different electronegativity• Bond formed by transfer of elect...
Ionic Bonds: One Big Greedy Thief Dog!
Naming Ionic Compound• All names have a predictable pattern.  • Name of the cation first, then the anion.     • Cation nam...
Section A: Complete the chart using a periodic table to help you.
Answer these questions:                                                        NEGATIVEAn atom that gains one or more elec...
What is an ionic bond?                                ELECTRONSAtoms will transfer one or more ________________ to another...
Example B3: Potassium + Iodine   Example B4: Sodium + OxygenExample B5: Calcium + Chlorine   Example B6: Aluminum + Chlorine
COVALENT BONDbond formed by thesharing of electrons
Covalent Bond• Between nonmetallic elements of similar  electronegativity.• Formed by sharing electron pairs• Stable non-i...
Bonds in all thepolyatomic ions and diatomicsare all covalent     bonds
NONPOLARCOVALENT BONDSwhen electrons are shared equally     H2 or Cl2
2. Covalent bonds- Two atoms share one or more pairs of outer-shellelectrons.             Oxygen Atom                   Ox...
POLAR COVALENT    BONDSwhen electrons areshared but shared    unequally       H2O
Polar Covalent Bonds: Unevenly matched, but willing to share.
- water is a polar molecule because oxygen is moreelectronegative than hydrogen, and therefore electronsare pulled closer ...
Polyatomic Ions• Covalently bonded group of atoms that has a  positive or negative charge and acts as a unit.          COM...
What is a covalent bond?       SHAREAtoms ___________ one or more electrons with each other to form the bond.             ...
Example C3: Chlorine + Chlorine   Example C4: Oxygen + OxygenExample C5: Carbon + 2 Oxygen     Example C6: Carbon + 4 Hydr...
METALLIC BOND  bond found inmetals; holds metal atoms together   very strongly
Metallic Bonds are…• How metal atoms are held together  in the solid.• Metals hold on to their valence  electrons very wea...
Sea of Electrons• Electrons are free to move through the  solid.• Metals conduct electricity.         +    + + +          ...
Metals are Malleable• Hammered into shape (bend).• Also ductile - drawn into wires.• Both malleability and ductility  expl...
Due to the mobility of the                                        Noticevalence electrons, metals have:         that the  ...
Malleable        +    + + +Force            + + + +             + + + +
Malleable• Mobile electrons allow atoms to slide by,  sort of like ball bearings in oil.                    + + + + Force ...
Ionic solids are brittleForce     +   -   +   -          -   +   -   +          +   -   +   -          -   +   -   +
Ionic solids are brittle• Strong Repulsion breaks a crystal apart, due  to similar ions being next to each other.         ...
Metallic Bonds: Mellow dogs with plenty         of bones to go around.
Ionic Bond, A Sea of Electrons
Alloys• We use lots of metals every day, but  few are pure metals• Alloys are mixtures of 2 or more  elements, at least 1 ...
Why use alloys?• Properties are often superior to the pure  element• Sterling silver (92.5% Ag, 7.5% Cu) is harder  and mo...
Metals Form AlloysMetals do not combine with metals. They formAlloys which is a solution of a metal in a metal.Examples ar...
Chapter 6:  Bonding Basics
Chapter 6:  Bonding Basics
Chapter 6:  Bonding Basics
Chapter 6:  Bonding Basics
Chapter 6:  Bonding Basics
Chapter 6:  Bonding Basics
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Chapter 6: Bonding Basics

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Chapter 6: Bonding Basics

  1. 1. • OBJECTIVES: –Determine the number of valence electrons in an atom of a representative element. –Explain how the octet rule applies to atoms of metallic and nonmetallic elements.
  2. 2. • OBJECTIVES: –Describe how cations form. –Explain how anions form. –Explain the electrical charge of an ionic compound.
  3. 3. • OBJECTIVES: –Describe how cations form. –Explain how anions form. –Explain the electrical charge of an ionic compound.
  4. 4. • OBJECTIVES: –Explain the electrical charge of an ionic compound. –Describe three properties of ionic compounds.
  5. 5. • OBJECTIVES: –Describe the arrangement of atoms in a metal. –Explain the importance of alloys.
  6. 6. The Octet RuleWe learned that noble gases are unreactive inchemical reactionsIn 1916, Gilbert Lewis used this fact toexplain why atoms form certain kinds of ionsand moleculesThe Octet Rule: in forming compounds,atoms tend to achieve a noble gasconfiguration; 8 in the outer level is stable Each noble gas (except He, which has 2) has 8 electrons in the outer level
  7. 7. Formation of Cations• Metals lose electrons to attain a noble gas configuration.• They make positive ions (cations)
  8. 8. Electron Dots For Cations• Metals will have few valence electrons (usually 3 or less); calcium has only 2 valence electrons Ca
  9. 9. Electron Dots For Cations• Metals will have few valence electrons• Metals will lose the valence electrons Ca
  10. 10. Electron Dots For Cations• Metals will have few valence electrons• Metals will lose the valence electrons• Forming positive ions Ca 2+ This is named the “calcium ion”.NO DOTS are now shown for the cation.
  11. 11. Electron Configurations: Anions• Nonmetals gain electrons to attain noble gas configuration.• They make negative ions (anions)
  12. 12. Electron Dots For Anions• Nonmetals will have many valence electrons (usually 5 or more)• They will gain electrons to fill outer shell. P 3- (This is called the “phosphide ion”, and should show dots)
  13. 13. Stable Electron Configurations• All atoms react to try and achieve a noble gas configuration.• 8 valence electrons = already stable!• This is the octet rule (8 in the outer level is particularly stable). Ar
  14. 14. Octet Rule = atoms tend to gain, lose or share electrons soas to have 8 electrons C would like to Gain 4 electrons N would like to Gain 3 electrons O would like to Gain 2 electrons
  15. 15. Learning Check A. X would be the electron dot formula for 1) Na 2) K 3) Al B.  X would be the electron dot formula  1) B 2) N 3) P
  16. 16. Chemical bonds: an attempt to fill electron shells 1. Ionic bonds – 2. Covalent bonds – 3. Metallic bonds
  17. 17. IONIC BONDbond formed between two ions by the transfer of electrons
  18. 18. Ionic Bonding — Ionic Compounds• Anions and cations are held together by opposite charges (+ and -)• Ionic compounds are called salts.• The bond is formed through the transfer of electrons (lose and gain)• Electrons are transferred to achieve noble gas configuration.
  19. 19. Ionic Bonding Na ClThe metal (sodium) tends to lose its oneelectron from the outer level.The nonmetal (chlorine) needs to gain onemore to fill its outer level, and will accept theone electron that sodium is going to lose.
  20. 20. Ionic Bonding Na Cl+ -Note: Remember that NO DOTSare now shown for the cation!
  21. 21. Ionic BondingLets do an example by combiningcalcium and phosphorus: Ca P• All the electrons must be accounted for, and each atom will have a noble gas configuration (which is stable).
  22. 22. Ionic BondingCa P
  23. 23. Ionic BondingCa 2+ P
  24. 24. Ionic BondingCa 2+ PCa
  25. 25. Ionic Bonding 3-Ca 2+ PCa
  26. 26. Ionic Bonding 3-Ca 2+ PCa P
  27. 27. Ionic Bonding 3-Ca 2+ PCa 2+ P
  28. 28. Ionic BondingCa 3-Ca 2+ PCa 2+ P
  29. 29. Ionic BondingCa 3-Ca 2+ PCa 2+ P
  30. 30. Ionic BondingCa 2+ 3-Ca 2+ PCa 2+ P 3-
  31. 31. Ionic Bonding = Ca3P2 Formula UnitThis is a chemical formula, whichshows the kinds and numbers of atoms inthe smallest representative particle of thesubstance.For an ionic compound, the smallestrepresentative particle is called a:Formula Unit
  32. 32. Properties of Ionic Compounds1. Crystalline solids - a regular repeating arrangement of ions in the solid: Fig. 5, page 162 – Ions are strongly bonded together. – Structure is rigid.2. High melting points• Coordination number- number of ions of opposite charge surrounding it
  33. 33. - Page 162 Coordination Numbers: Both the sodiumNaCl and chlorine have 6 Both the cesiumCsCl and chlorine have 8 Each titanium hasTiO2 6, and each oxygen has 3
  34. 34. Do they Conduct?• Conducting electricity means allowing charges to move.• In a solid, the ions are locked in place.• Ionic solids are insulators.• When melted, the ions can move around.3. Melted ionic compounds conduct. – NaCl: must get to about 800 ºC. – Dissolved in water, they also conduct (free to move in aqueous solutions)
  35. 35. Formation of Ions from MetalsIonic compounds result when metals react with nonmetalsMetals lose electrons to match the number of valence electrons of their nearest noble gasPositive ions form when the number of electrons are less than the number of protons Group 1 metals → ion 1+ Group 2 metals → ion 2+• Group 13 metals → ion 3+
  36. 36. Formation of Sodium IonSodium atom Sodium ion Na • – e− → Na +2-8-1 2-8 ( = Ne) 11 p+ 11 p+ 11 e- 10 e- 0 1+
  37. 37. Formation of Magnesium IonMagnesium atom Magnesium ion• Mg • – 2e− → Mg2+2-8-2 2-8 (=Ne) 12 p+ 12 p+ 12 e- 10 e- 0 2+
  38. 38. Some Typical Ions with Positive Charges (Cations)Group 1 Group 2 Group 13H+ Mg2+ Al3+Li+ Ca2+Na+ Sr2+K+ Ba2+
  39. 39. Learning CheckA. Number of valence electrons in aluminum 1) 1 e- 2) 2 e- 3) 3 e-B. Change in electrons for octet 1) lose 3e- 2) gain 3 e- 3) gain 5 e-C. Ionic charge of aluminum 1) 3- 2) 5- 3) 3+
  40. 40. SolutionA. Number of valence electrons in aluminum 3) 3 e-B. Change in electrons for octet 1) lose 3e-C. Ionic charge of aluminum 3) 3+
  41. 41. Learning CheckGive the ionic charge for each of the following:A. 12 p+ and 10 e- 1) 0 2) 2+ 3) 2-B. 50p+ and 46 e- 1) 2+ 2) 4+ 3) 4-C. 15 p+ and 18e- 2) 3+ 2) 3- 3) 5-
  42. 42. Ions from Nonmetal IonsIn ionic compounds, nonmetals in 5A, 6A, and 7A gain electrons from metalsNonmetals add electrons to achieve the octet arrangementNonmetal ionic charge: 3-, 2-, or 1-
  43. 43. Fluoride Ion unpaired electron octet •• •• 1-:F• + e− : F: •• ••2-7 2-8 (= Ne)9 p+ 9 p+9 e- 10 e-0 1- ionic charge
  44. 44. Ionic Bond• Between atoms of metals and nonmetals with very different electronegativity• Bond formed by transfer of electrons• Produce charged ions all states. Conductors and have high melting point.• Examples; NaCl, CaCl2, K2O
  45. 45. Ionic Bonds: One Big Greedy Thief Dog!
  46. 46. Naming Ionic Compound• All names have a predictable pattern. • Name of the cation first, then the anion. • Cation name remains the same • Anion name will end in –ide. • EXAMPLE: Sodium Chloride• COMMON ANIONS • Fluorine  Fluoride • Chlorine  Chloride • Bromine  Bromide • Iodine  Iodide • Oxygen  Oxide • Sulfur  Sulfide • Nitrogen  Nitride • Phosphorus  Phosphide
  47. 47. Section A: Complete the chart using a periodic table to help you.
  48. 48. Answer these questions: NEGATIVEAn atom that gains one or more electrons will have a ____________________charge. POSITIVEAn atom that loses one or more electrons will have a ____________________charge. IONAn atom that gains or loses one or more electrons is called an ____________. CATIONA positive ion is called a ______________ and a negative ion is called an ANION_______________. “Cat-Eye- “An-Eye- On” On”
  49. 49. What is an ionic bond? ELECTRONSAtoms will transfer one or more ________________ to another to form the bond. COMPLETEEach atom is left with a ________________ outer shell. METALAn ionic bond forms between a ___________ ion with a positive charge and a NONMETAL________________ ion with a negative charge.Example B1: Sodium + Chlorine Example B2: Magnesium + Iodine
  50. 50. Example B3: Potassium + Iodine Example B4: Sodium + OxygenExample B5: Calcium + Chlorine Example B6: Aluminum + Chlorine
  51. 51. COVALENT BONDbond formed by thesharing of electrons
  52. 52. Covalent Bond• Between nonmetallic elements of similar electronegativity.• Formed by sharing electron pairs• Stable non-ionizing particles, they are not conductors at any state• Examples; O2, CO2, C2H6, H2O, SiC
  53. 53. Bonds in all thepolyatomic ions and diatomicsare all covalent bonds
  54. 54. NONPOLARCOVALENT BONDSwhen electrons are shared equally H2 or Cl2
  55. 55. 2. Covalent bonds- Two atoms share one or more pairs of outer-shellelectrons. Oxygen Atom Oxygen Atom Oxygen Molecule (O2)
  56. 56. POLAR COVALENT BONDSwhen electrons areshared but shared unequally H2O
  57. 57. Polar Covalent Bonds: Unevenly matched, but willing to share.
  58. 58. - water is a polar molecule because oxygen is moreelectronegative than hydrogen, and therefore electronsare pulled closer to oxygen.
  59. 59. Polyatomic Ions• Covalently bonded group of atoms that has a positive or negative charge and acts as a unit. COMMON POLYATOMIC IONS• Ammonium -- NH4 • Phosphate -- PO4• Hydroxide -- OH • Chromate -- CrO4• Nitrate -- NO3 • Silicate -- SiO3• Sulfate -- SO4 • Acetate -- C2H3O2• Carbonate -- CO3 • Peroxide -- O2
  60. 60. What is a covalent bond? SHAREAtoms ___________ one or more electrons with each other to form the bond. COMPLETEEach atom is left with a ________________ outer shell. NONMETALA covalent bond forms between two _________________.Example C1: Hydrogen + Hydrogen Example C2: 2 Hydrogen + Oxygen
  61. 61. Example C3: Chlorine + Chlorine Example C4: Oxygen + OxygenExample C5: Carbon + 2 Oxygen Example C6: Carbon + 4 Hydrogen
  62. 62. METALLIC BOND bond found inmetals; holds metal atoms together very strongly
  63. 63. Metallic Bonds are…• How metal atoms are held together in the solid.• Metals hold on to their valence electrons very weakly.• Think of them as positive ions (cations) floating in a sea of electrons
  64. 64. Sea of Electrons• Electrons are free to move through the solid.• Metals conduct electricity. + + + + + + + + + + + +
  65. 65. Metals are Malleable• Hammered into shape (bend).• Also ductile - drawn into wires.• Both malleability and ductility explained in terms of the mobility of the valence electrons
  66. 66. Due to the mobility of the Noticevalence electrons, metals have: that the ionic 1) Ductility and 2) Malleability crystal breaks due to ion repulsion!
  67. 67. Malleable + + + +Force + + + + + + + +
  68. 68. Malleable• Mobile electrons allow atoms to slide by, sort of like ball bearings in oil. + + + + Force + + + + + + + +
  69. 69. Ionic solids are brittleForce + - + - - + - + + - + - - + - +
  70. 70. Ionic solids are brittle• Strong Repulsion breaks a crystal apart, due to similar ions being next to each other. + - + - Force - + - + + - + - - + - +
  71. 71. Metallic Bonds: Mellow dogs with plenty of bones to go around.
  72. 72. Ionic Bond, A Sea of Electrons
  73. 73. Alloys• We use lots of metals every day, but few are pure metals• Alloys are mixtures of 2 or more elements, at least 1 is a metal• made by melting a mixture of the ingredients, then cooling• Brass: an alloy of Cu and Zn• Bronze: Cu and Sn
  74. 74. Why use alloys?• Properties are often superior to the pure element• Sterling silver (92.5% Ag, 7.5% Cu) is harder and more durable than pure Ag, but still soft enough to make jewelry and tableware• Steels are very important alloys – corrosion resistant, ductility, hardness, toughness, cost
  75. 75. Metals Form AlloysMetals do not combine with metals. They formAlloys which is a solution of a metal in a metal.Examples are steel, brass, bronze and pewter.

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