Review Quiz

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Class Topics
Title General Science 3/31/08
Objectives

• To learn about atoms and molecules

• Review Quiz
• Review Chemical reactions
• Ionic bonding
• Covalent bonds
• ""An important scientific innovation rarely makes
  its way by gradually winning over and converting
  its opponents it rarely happens that Saul
  becomes Paul. What does happen is that its
  opponents gradually die out and that the growing
  generation is familiarized with the idea from the
  beginning."
• Max Planck, 1936

Saturday, December 26, 2009 938 AM
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Class Assignments
By When
What

• Read 146-149 3/31/08
• Opinion of genetic engineering (7th only) 3/31/08
• W.S. 1 Bonding and equations 4/1/08
• Due this class period
• Due next class period
• Due in the future

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Ionic Bonding

• Sodium Chloride
• Transfer of electrons
• Ions are formed
• Held together by charges
• Weaker bond

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Ionic Bonds

• Valence electrons
• Those electrons that are found in an elements
  outer shell
• Sodium
• Gain __ electrons
• Lose __ electron
• Chlorine
• Gain __ electron
• Lose __ electrons

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Ionic bonds

• Examples
• Properties
• High melting point
• Poor conductor of electricity (solid state)
• Good conductor in liquid state
• Poor malleability

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Common Ions
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Covalent Bonding

• Sharing of electrons
• Stronger bond
• CO2
• O2
• H20
• C6H12O6

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Covalent bonding

• Double bonds
• Carbon dioxide
• Triple bonds
• nitrogen

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Metals, Metalloids, Nonmetals

• Metals
• Good conductors of heat and electricity
• Solids at room temp. (one exception)
• Most are malleable, and ductile
• Nonmetals
• Poor conductors of heat and electricity
• Most are gases at room temp.
• Metalloids
• Properties that fall between metals and nonmetals

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Chemical Reactions

• When a substance undergoes a chemical change
• Existing bonds break and new bonds form making
  new substances
• Evidence

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Chemical Reactions

• Reactants Products
• Example burning charcoal (pure carbon)
• C O2 CO2
• 6CO2 6 H20 C6H12O6 6O2
• Hydrazine oxygen nitrogen water
• N2H4 O2 N2 H20

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Conservation of Mass

• In a chemical reaction no mass or energy is lost
  nor gained
• It changes form
• Reactants products

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Types of Reactions

• Synthesis
• Two or more substances combine to form one
  substance
• Sodium and Chlorine
• Sodium chloride
• Hydrogen and oxygen
• water

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Types of Reactions

• Decomposition

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Energy and reactions

• exothermic

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Energy and reactions

• Endothermic

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Conservation of Energy
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Reaction Rate
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Catalysts
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LabUsing clues to identify elements

• Clues
• Adjust 10, 12
• When you have finished
• In your notebook, answer the questions from p.
  164 (1-8)