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Chapter 7

Chapter 7. Ionic Compounds and Metals. National Standards for Chapter 7. UCP.1 – Systems, order, and organization UCP.2 – Evidence, models, and explanation A.1 –Abilities necessary to do scientific inquiry B-1 – Structure of atoms B-2 – Structure and properties of matter

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Chapter 7

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  1. Chapter 7 Ionic Compounds and Metals

  2. National Standards for Chapter 7 • UCP.1 – Systems, order, and organization • UCP.2 – Evidence, models, and explanation • A.1 –Abilities necessary to do scientific inquiry • B-1 – Structure of atoms • B-2 – Structure and properties of matter • B-3 – Chemical reactions • B-4 – Motions and forces • B-6 – Interactions of energy and matter • E-1 – Abilities of technological design • E-2 – Understandings about science and technology • G.2 – Nature of scientific knowledge

  3. Vocabulary/Study Guide • Define each term using the Glossary • Either write on the handout, or use your own paper • This is due on Test Day, Wednesday, December 18

  4. Section 1: Ion Formation National Standards: • UCP.1 – Systems, order, and organization • UCP.2 – Evidence, models, and explanation • A.1 –Abilities necessary to do scientific inquiry • B-1 – Structure of atoms • B-2 – Structure and properties of matter

  5. Objectives – Section 1 • Define a chemical bond. • Describe the formation of positive and negative ions. • Relate ion formation to electron configuration. REVIEW VOCABULARY: • octet rule: atoms tend to gain, lose, or share electrons in order to acquire eight valence electrons • ionization energy: refers to how easily an atom loses an electron • electron affinity: indicates how much attraction an atom has for electrons

  6. New Vocabulary • chemical bond • cation • anion • Ions are formed when atoms gain or lose valence electrons to achieve a stable octet electron configuration.

  7. Valence Electrons and Chemical Bonds • A chemical bond is the force that holds two atoms together. • Chemical bonds form by the attraction between the positive nucleus of one atom and the negative electrons of another atom.

  8. Valence Electrons and Chemical Bonds • Atom’s try to form the octet—the stable arrangement of eight valence electrons in the outer energy level—by gaining or losing valence electrons.

  9. Positive Ion Formation • A positively charged ion is called a cation. • This figure illustrates how sodium loses one valence electron to become a sodium cation.

  10. Positive Ion Formation • Metals are reactive because they lose valence electrons easily.

  11. Positive Ion Formation • Transition metals commonly form 2+ or 3+ ions, but can form greater than 3+ ions. • Other relatively stable electron arrangements are referred to as pseudo-noble gas configurations.

  12. Negative Ion Formation • An anionis a negatively charged ion. • The figure shown here illustrates chlorine gaining an electron to become a chlorine ion.

  13. Negative Ion Formation • Nonmetal ions gain the number of electrons required to fill an octet. • Some nonmetals can gain or lose electrons to complete an octet.

  14. Transparency 22: Formation of Ions

  15. Math Transparency 7: Calculating Number of Electrons and Predicting Ionic Change

  16. Homework, Section 1 • SECTION 1 REVIEW, Page 209 • Questions #1-6 • Answer with complete sentences • Due tomorrow

  17. Section 2: Ionic Bonds and Ionic Compounds National Standards: • UCP.1 – Systems, order, and organization • UCP.2 – Evidence, models, and explanation • B-1 – Structure of atoms • B-2 – Structure and properties of matter • B-3 – Chemical reactions • B-4 – Motions and forces • B-6 – Interactions of energy and matter

  18. Objectives – Section 2 • Describethe formation of ionic bonds and the structure of ionic compounds. • Generalizeabout the strength of ionic bonds based on the physical properties of ionic compounds. • Categorizeionic bond formation as exothermic or endothermic. Review Vocabulary: • compound:a chemical combination of two or more different elements

  19. New Vocabulary • ionic bond • ionic compound • crystal lattice • electrolyte • lattice energy • Oppositely charged ions attract each other, forming electrically neutral ionic compounds.

  20. Formation of an Ionic Bond • The electrostatic force that holds oppositely charged particles together in an ionic compound is called an ionic bond. • Compounds that contain ionic bonds are called ionic compounds. • Binary ionic compounds contain only two different elements—a metallic cation and a nonmetallic anion.

  21. Formation of an Ionic Bond

  22. Mini-Lab: What compounds conduct electricity in solution?

  23. Transparency 23: Ionic Bonds

  24. Practice Problems #7-11, page 212

  25. Properties of Ionic Compounds • Positive and negative ions exist in a ratio determined by the number of electrons transferred from the metal atom to the non-metal atom. • The repeating pattern of particle packing in an ionic compound is called an ionic crystal.

  26. Properties of Ionic Compounds • The strong attractions among the positive and negative ions result in the formation of the crystal lattice. • A crystal latticeis the three-dimensional geometric arrangement of particles, and is responsible for the structure of many minerals.

  27. Properties of Ionic Compounds • Melting point, boiling point, and hardness depend on the strength of the attraction.

  28. Properties of Ionic Compounds • In a solid, ions are locked into position and electrons cannot flow freely—solid ions are poor conductors of electricity. • Liquid ions or ions in aqueous solution have electrons that are free to move, so they conduct electricity easily. • An ion in aqueous solution that conducts electricity is an electrolyte.

  29. Properties of Ionic Compounds • This figure demonstrates how and why crystals break when an external force is applied.

  30. Lab: Synthesize an Ionic Compound, page 230

  31. Lab: Properties of Ionic Compounds

  32. Energy and the Ionic Bond • Reactions that absorb energy are endothermic. • Reactions that release energy are exothermic.

  33. Energy and the Ionic Bond • The energy required to separate 1 mol of ions in an ionic compound is referred to as the lattice energy. • Lattice energy is directly related to the size of the ions that are bonded.

  34. Energy and the Ionic Bond • Smaller ions form compounds with more closely spaced ionic charges, and require more energy to separate. • Electrostatic force of attraction is inversely related to the distance between the opposite charges. • The smaller the ion, the greater the attraction.

  35. Energy and the Ionic Bond • The value of lattice energy is also affected by the charge of the ion.

  36. Data Analysis Lab: Interpret Data, page 216 • Can embedding nanoparticles of silver into a polymer give the polymer antimicrobial properties?

  37. Lab: Formation of a Salt

  38. Homework, Section 2 • SECTION 2 REVIEW, Page 217 • Questions #12-18 • Answer with complete sentences • Due tomorrow

  39. Section 3: Names and Formulas for Ionic Compounds National Standards: • UCP.1 – Systems, order, and organization • UCP.2 – Evidence, models, and explanation • B-2 – Structure and properties of matter • E-2 – Understandings about science and technology • G.2 – Nature of scientific knowledge

  40. Objectives – Section 3 • Relatea formula unit of an ionic compound to its composition. • Writeformulas for ionic compounds and oxyanions. • Applynaming conventions to ionic compounds and oxyanions. Review Vocabulary: • nonmetal:an element that is generally a gas or a dull, brittle solid and is a poor conductor of heat and electricity

  41. New Vocabulary • formula unit • monatomic ion • oxidation number • polyatomic ion • oxyanion • In written names and formulas for ionic compounds, the cation appears first, followed by the anion.

  42. Formulas for Ionic Compounds • When writing names and formulas for ionic compounds, the cation appears first followed by the anion. • Chemists around the world need to communicate with one another, so a standardized system of naming compounds was developed.

  43. Formulas for Ionic Compounds • A formula unit represents the simplest ratio of the ions involved. • Monatomic ionsare one-atom ions.

  44. Formulas for Ionic Compounds • Oxidation number, or oxidation state, is the charge of a monatomic ion.

  45. Formulas for Ionic Compounds • The symbol for the cation is always written first, followed by the symbol of the anion. • Subscripts represent the number of ions of each element in an ionic compound. • The total charge must equal zero in an ionic compound.

  46. Formulas for Ionic Compounds • Polyatomic ionsare ions made up of more than one atom. • Since polyatomic ions exist as a unit, never change subscripts of the atoms within the ion. If more than one polyatomic ion is needed, place parentheses around the ion and write the appropriate subscript outside the parentheses.

  47. Formulas for Ionic Compounds

  48. Transparency 24: Formulas for Ionic Compounds

  49. Math Transparency 8: Determining Numbers of Ions

  50. Practice problems #19-23, page 221 • Practice problems #24-27, page 222

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