Chapter 2: Molecules, Ions, and Compounds

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Chapter 2 Molecules, Ions, and Compounds

• MACROSCOPIC SCALE
• Elements combine to make compounds.
• ATOMIC SCALE
• Atoms combine to make molecules, or extended
  structures.

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What well cover

• Compound Formulas
• Ions
• Monatomic
• Polyatomic
• Ionic Compounds
• Molecular Compounds
• Other types of extended Structures

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Compound Formulas

• Examples
• NaCl
• CH3OH
• (NH4)2SO4

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Three Types of Compounds

• Molecular Covalent Extended
  Covalent
• Ionic

Alloys
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Can you predict this?
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Types of Formulas
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IONS

• Cations
• Formed by losing electrons.
• Have a positive charge.
• Formed mainly from metals.

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IONS

• Cations
• Formed by losing electrons.
• Have a positive charge.
• Formed mainly from metals.

Anions Formed by gaining electrons. Have a
negative charge. Formed mainly from nonmetals.
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Monatomic Ions- Formed from single atoms
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Naming IONS

• Cations
• Name of element ion
• Na sodium ion
• Mg2 magnesium ion

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Naming IONS

• Cations
• Name of element ion
• Na sodium ion
• Mg2 magnesium ion

Anions Name of element with ide ending
ion Cl- chloride ion O2- oxide ion
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Polyatomic Ions you need to know
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Ionic Compound Formulas

• Total cation charge Total anion charge
• Ex Na and Cl- make ________

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Ionic Compound Formulas

• Total cation charge Total anion charge
• Ex Na and Cl- make NaCl
• Mg2 and Cl- make ________

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Ionic Compound Formulas

• Total cation charge Total anion charge
• Ex Na and Cl- make NaCl
• Mg2 and Cl- make MgCl2
• NH4 and SO42- make _________

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Naming Ionic Compounds

• Name cation name anion name
• Ex
• NaCl
• NH4Br

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Molecular Compounds

• Nonmetal nonmetal gives molecular compound

Ex C O S O C H
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Aside on gas prices
Propane Butane Jet Fuel Gasoline Diesel/Heating Lo
nger molecules(asphalt/tar)
Crude oil
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Predicting Molecular Compound Formulas
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Naming Molecular Compounds

• Binary Compounds form between 2 elements

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Naming Molecular Compounds

• Binary Compounds form with 2 elements
• Element with highest group named last, like
  its an anion.

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Naming Molecular Compounds

• Binary Compounds form with 2 elements
• Element with highest group named last, like
  its an anion.
• Use prefixes to indicate numbers
• 2 di
• 3 tri
• 4 tetra
• 5 penta

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Network Solids

• Held together like a molecule
• Large and extended