chapter 15 ionic bonding and ionic compounds n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Chapter 15 Ionic Bonding and Ionic Compounds PowerPoint Presentation
Download Presentation
Chapter 15 Ionic Bonding and Ionic Compounds

Loading in 2 Seconds...

play fullscreen
1 / 47

Chapter 15 Ionic Bonding and Ionic Compounds - PowerPoint PPT Presentation


  • 595 Views
  • Uploaded on

Chapter 15 Ionic Bonding and Ionic Compounds. Milbank High School. Section 15.1 Electron Configuration in Ionic Bonding. OBJECTIVES: Use the periodic table to infer the number of valence electrons in an atom, and draw it’s electron dot structure.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Chapter 15 Ionic Bonding and Ionic Compounds


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
    Presentation Transcript
    1. Chapter 15Ionic Bonding and Ionic Compounds Milbank High School

    2. Section 15.1Electron Configuration in Ionic Bonding • OBJECTIVES: • Use the periodic table to infer the number of valence electrons in an atom, and draw it’s electron dot structure.

    3. Section 15.1Electron Configuration in Ionic Bonding • OBJECTIVES: • Describe the formation of cations from metals, and of anions from nonmetals.

    4. Valence Electrons • The electrons responsible for the chemical properties of atoms are those in the outer energy level. • Valence electrons - The s and p electrons in the outer energy level • the highest occupied energy level • Core electrons -those in the energy levels below.

    5. Keeping Track of Electrons • Atoms in the same column... • Have the same outer electron configuration. • Have the same valence electrons. • Easily found: group number on the periodic table for representative elem. • Group 2A: Be, Mg, Ca, etc. • 2 valence electrons

    6. Electron Dot diagrams • Write the symbol. • Put one dot for each valence electron • Don’t pair up until they have to (Hund’s rule) X

    7. The Electron Dot diagram for Nitrogen • Nitrogen has 5 valence electrons. • First we write the symbol. N • Then add 1 electron at a time to each side. • Until they are forced to pair up.

    8. Write electron dot diagrams: • Na • Mg • C • O • F • Ne • V

    9. Electron Configurations for Cations • Metals lose electrons to attain noble gas configuration. • They make positive ions (cations) • If we look at the electron configuration, it makes sense to lose electrons: • Na 1s22s22p63s1 1 valence electron • Na1+1s22s22p6 noble gas configuration

    10. Electron Dots For Cations • Metals will have few valence electrons (usually 3 or less) Ca

    11. Electron Dots For Cations • Metals will have few valence electrons • These will come off Ca

    12. Electron Dots For Cations • Metals will have few valence electrons • These will come off • Forming positive ions Ca2+

    13. Electron Configurations for Anions • Nonmetals gain electrons to attain noble gas configuration. • They make negative ions (anions) • Halide ions- ions from chlorine or other halogens that gain electrons • S 1s22s22p63s23p4 6 valence electrons • S2-1s22s22p63s23p6 noble gas configuration.

    14. Electron Dots For Anions • Nonmetals will have many valence electrons (usually 5 or more) • They will gain electrons to fill outer shell. P P3-

    15. Stable Electron Configurations • All atoms react to achieve noble gas configuration. • Noble gases have 2 s and 6 p electrons. • 8 valence electrons . • Also called the octet rule. Ar

    16. Section 15.2Ionic Bonds • OBJECTIVES: • List the characteristics of an ionic bond.

    17. Section 15.2Ionic Bonds • OBJECTIVES: • Use the characteristics of ionic compounds to explain the electrical conductivity of ionic compounds when melted and when in aqueous solution.

    18. Ionic Bonding • Anions and cations are held together by opposite charges. • Ionic compounds are called salts. • Simplest ratio is called the formula unit. • The bond is formed through the transfer of electrons. • Electrons are transferred to achieve noble gas configuration.

    19. Ionic Bonding Na Cl

    20. Ionic Bonding Na+ Cl-

    21. Ionic Bonding • All the electrons must be accounted for! Ca P

    22. Ionic Bonding Ca P

    23. Ionic Bonding Ca2+ P

    24. Ionic Bonding Ca2+ P Ca

    25. Ionic Bonding Ca2+ P 3- Ca

    26. Ionic Bonding Ca2+ P 3- Ca P

    27. Ionic Bonding Ca2+ P 3- Ca2+ P

    28. Ionic Bonding Ca Ca2+ P 3- Ca2+ P

    29. Ionic Bonding Ca Ca2+ P 3- Ca2+ P

    30. Ionic Bonding Ca2+ Ca2+ P 3- Ca2+ P 3-

    31. Ionic Bonding = Ca3P2 Formula Unit Sample Problem 15-1, page 421

    32. Properties of Ionic Compounds • Crystalline structure, usually solids • A regular repeating arrangement of ions in the solid: Fig. 15.9, p.423 • Ions are strongly bonded together. • Structure is rigid. • High melting points • Coordination number- number of ions of opposite charge surrounding it

    33. Do they Conduct? • Conducting electricity is allowing charges to move. • In a solid, the ions are locked in place. • Ionic solids are insulators. • When melted, the ions can move around. • Melted ionic compounds conduct. • NaCl: must get to about 800 ºC. • Dissolved in water they conduct (aqueous)

    34. Section 15.3Bonding in Metals • OBJECTIVES: • Use the theory of metallic bonds to explain the physical properties of metals.

    35. Section 15.3Bonding in Metals • OBJECTIVES: • Describe the arrangements of atoms in some common metallic crystal structures.

    36. Metallic Bonds • How 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: Fig. 15.13, p.427

    37. + + + + + + + + + + + + Sea of Electrons • Electrons are free to move through the solid. • Metals conduct electricity.

    38. 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 • Fig. 15.14, p.427

    39. + + + + + + + + + + + + Malleable

    40. + + + + + + + + + + + + Malleable • Electrons allow atoms to slide by.

    41. + - + - - + - + + - + - - + - + Ionic solids are brittle

    42. - + - + - + - + + - + - - + - + Ionic solids are brittle • Strong Repulsion breaks crystal apart.

    43. Crystalline structure of metal • If made of one kind of atom, metals are among the simplest crystals • Note Fig. 15.16, p.428 for types: 1. Body-centered cubic: • every atom has 8 neighbors • Na, K, Fe, Cr, W

    44. Crystalline structure of metal 2. Face-centered cubic: • every atom has 12 neighbors • Cu, Ag, Au, Al, Pb 3. Hexagonal close-packed • every atom also has 12 neighbors • different pattern due to hexagonal • Mg, Zn, Cd

    45. Alloys • Alloys - mixtures of 2 or more elements, at least 1 is a metal • Brass: an alloy of Cu and Zn • Bronze: Cu and Sn

    46. Why use alloys? • 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

    47. Why use alloys? • Table 15.3, p.429 - common alloys • Types? a) substitutional alloy- the atoms in the components are about the same size • b) interstitial alloy- the atomic sizes quite different; smaller atoms fit into the spaces between larger • Amalgam- dental use, contains Hg