Ionic Bonds

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Ionic Bonds

• Chemistry
• Mrs. Coyle

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Part A

• Ions
• Lewis Dot Structure
• Stable Octet (or Duet)

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The Periodic Table and Atomic Radius
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Valence Electrons

• Valence electrons are the electrons in the
  highest occupied energy level of the atom.
• Valence electrons are the only electrons
  generally involved in bond formation.

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Electron Configuration of Sodium

• 1s2 2s2 2p6 3s1
• Which is the valence electron for Na?
• Answer 1s2 2s2 2p6 3s1

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Na , 11 e
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Na , 10e
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A Positive Ion (Cation)

• An atom that has lost one or more electrons.
• charge

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Electron Dot Structure or Lewis Dot Diagram

• A notation showing the valence electrons
  surrounding the atomic symbol.

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Elements within the same group have the same
electron-dot structure.
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A Negative Ion (Anion)

• An atom that has gained one or more electrons.
• Negatively (-) charged.

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Chlorine Atom ? Chlorine Ion
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When Na, (Z 11) loses its valence electron, what
element does its configuration look like ?
Check your Neighbor

• Neon
• Potassium
• Beryllium
• Sodium

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When Na, (Z 11) loses its valence electron, what
element does its configuration look like ?
Check your Neighbor

• Neon
• Potassium
• Beryllium
• Sodium

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A Stable Octet
When the valence shell is full, the atom is
stable, less likely to react. Example Noble
(Inert Gases)
Kr
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Note

• Atoms tend to react in a way that would lead them
  to have a stable octet.

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Part B

• Equations for Formation of Ions and Naming Ions
• Ionic Bonds and Ionic Compounds

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Equations for the Formation of Cations

• H ? H e-
• Li ? Li e-
• Mg ? Mg2 2e-

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Equations for the Formation of Anions

• . ..
• F e- ? F -
• .. ..

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Naming cations ().

• Use the name of the metal.
• Example Na
• Sodium ion.

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Naming Anions(-)

• Use the name of the nonmetal with the ending
  ide.
• Example F-
• Fluoride

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Ionic Compounds

• Are made up of
• a metal and a nonmetal ion.
• polyatomic ions.

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Naming Ionic Compounds, a First Look

• Example NaF
• Sodium Fluoride

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Example

• Which of the following compounds are ionic?
• NaCl
• CO2
• CO
• KF
• KNO3

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Some Common Ions
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Bonding

• Elements that do not have a complete octet, tend
  to react.
• When the elements react bonds are formed.

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Types of Bonds

• Ionic
• Metallic
• Covalent

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Ionic Bonds

• Bonds that are formed by transfer of electrons
  from one element to the other.
• Each element (now an ion) will have a complete
  octet after the transfer of electrons.

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The Ionic Bond

• The electrical force of attraction between
  oppositely charged ions.

F-
Na
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Example Formation of Lithium Fluoride

• . ..
• Li. F ? Li F -
• ..
  ..

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Is an Ionic Compound Electrically Neutral or
Charged?
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Movie Clip

• http//www.youtube.com/watch?vKj3o0XvhVqQNR1

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Chemical Formula

• A representation of the kinds and number of atoms
  in a substance.

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Formula Unit

• A chemical formula that shows the lowest whole
  number ratio of the atoms (ions) in an ionic
  compound.
• Example KCl, Mg Cl2

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The formula unit is used because ionic compounds
have a lattice arrangement of ions. Ex NaCl

• Which ball represents the Na?