CHEMICAL BONDS

1
CHEMICAL BONDS

• How atoms combine to form different bonds
• How to predict what type of bond will form

2
TYPES OF BONDS

• Electrons are what cause atoms to bond.
• Two main types of bonding
• IONIC bonding atoms transfer electrons
• COVALENT bonding atoms share electrons

3
IONIC BONDS

• Held by /- attraction
• Form ions (e- transfer) conduct electricity
• OPPOSITE sides of Periodic Table
• non-metal metal

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IONIC BONDING

• PRACTICE draw the formation of sodium chloride
• Step 1 Na Cl ? Na Cl
• Step 2 draw dots around the reactants
• Step 3 draw dots and charges around the
  products

sodium gives e leaving it with a full valence
orbital
chlorine gains e- leaving it with a full valence
orbital
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PREDICTING IONIC BONDING

• Opposite sides of PT (i.e. metal non-metal)
• Big difference in Electronegativity ( 1.8)

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NAMING IONIC COMPOUNDS

1. Name of 1st element (metal)
2. Root of 2nd element (nonmetal)
3. Root -ide

MgOmagnesium oxygen ?
magnesium oxide
LiFlithium fluorine ?
lithium fluoride
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COVALENT BONDS

• Held by sharing electrons(cotogether valentvale
  nce e-)
• Does NOT conduct electricity
• Usually same side of PT

non-metal non-metal or metal metal Special
type of covalent is metal to metal metallic bond
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COVALENT BONDING
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PREDICTING COVALENT BONDING

• Same sides of PT (non-metal non-metal)
• Small difference in Electronegativity (lt 1.8)

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NAMING COVALENT COMPOUNDS

• Same as ionic (add ide)
• Add prefixes
• First Word
• 1 (understood)
• 2 di
• 3 tri
• 4 tetra
• 5 penta
• 6 hexa

• Second Word
• 1 mono
• 2 di
• 3 tri
• 4 tetra
• 5 penta
• 6 hexa

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PRACTICE NAMING

• CO
• Carbon monoxide
• CO2
• Carbon dioxide
• SO2
• sulfur dioxide
• CCl4
• Carbon tetrachloride

H2O Dihydrogen monoxide Si5P4 Pentasilicon
tetraphosphide
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PREDICTING BONDS USING PT ELECTRONEGATIVITY

• How can you tell if a bond is ionic or covalent?
• Opposite or same sides of PT (covalent SAME)
• ELECTRONEGATIVITY! (the ability to attract e-)
• Electronegativity difference 1.8 IONIC
• lt 1.8 COVALENT

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Bonding practice

• Na Cl
• 0.9 3.0
• 3.0
• -.9
• 2.1 gt1.8? Yes!
• IONIC

Na Cl metal non-metal Opposite
sides? Yes! IONIC
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Bonding practice

• C Cl
• non-metal non-metal
• Opposite side?
• No! COVALENT

C Cl 2.5 3.0 3.0 -2.5 0.5 gt1.8?
No! COVALENT