Day 8 in SCI110: Chemistry and Water

Spring 2006 Schedule
Last time:
- More discussion of the periodic table, and electron configurations
  - Electron theory of chemical bonding
  - Electron dot notation
  - ions
- Discussion of results of experiment (metals versus non-metals)
- Experiment - physical and chemical changes -- p. 37-39
Today:
- Review of reading, chapter 9 (bonds, ions)
  - The elements
  - Valence electrons - electrons in the outer shell (Electron theory of chemical bonding says these are the important ones....)
  - Chemical bond - an attractive force that holds atoms together in a compound
    - ionic bonds - atoms transfer electrons
      - ionic compounds - compounds held together by ionic bonds:
        
        NaCl - sodium chloride
        MgF₂ - magnesium flouride
      - Made with Metals and Nonmetals
      - Create ordered assemblage of charged particles.
      - Weaker
    - covalent bonds - atoms share electrons
      - H₂
      - F₂
      - double bond: C₂H₄ - ethylene
      - triple bond: C₂H₂ - Acetylene
      - Made of Nonmetals
      - Create molecules
      - Stronger
  - Parallel Exercises, p. 213: Group B, 1-3
- Discuss results of physical and chemical changes experiment
- Investigation of properties of water
  - Tim and Moby on Water
  - Physical Properties of Water (Workbook, p. 41)
    - Water properties, water measurements
    - water quiz
    - Discussion
    - Questions for Thought: 4, 5, 7-10
  - Acids and Bases
    - Tim and Moby
      - Acids and Bases
      - pH - potential of hydrogen - pouvoir hydrogene
      - mole - an Avogadro's number of something - 6.02 x 110²³ units (number of carbon atoms in 12 grams of carbon-12 is a mole).
    - Dissociation of water into hydronium and hydroxide ions
      - H₃O⁺ - hydronium ions - acidic - lookin' for love, or at least an electron
      - HO^- - hydroxide ions - basic - got electrons to burn....
    - Worksheet, pp. 42-43
    - Water chemistry and pH
  - T-test web overview
- Homework:
  - Polish your group project proposals
    - Remember: groups of 2 or 3 -- no more.
    - Provide a one-page proposal on Wednesday, including the names of group participants.
Links:
- What is the difference between a physical change and a chemical change?
- Dr. Walt Volland's on-line chemistry pages

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