Graphic Organizer for Bonding

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Graphic Organizer for Bonding
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Covalent Bonding

• Bonding between non-metals and non-metals.
• All atoms included have fairly high
  electronegativity and few vacancies in valence
  energy levels.
• When they bond, they gain electrons to achieve
  stable configuration.
• Hence, electrons are shared.

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Element abundance
most abundant
96.3
trace
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Covalence

• Sharing produces low energy (stable) electron
  arrangements.
• Noble gas configuration
• Full outer shell (He 2 Ne 2,8, Ar 2,8,8)
• Covalence is the number of electrons an atom
  needs to gain to produce a stable outer shell.

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Simple Covalent Bond

• Hydrogen gas forms the simplest covalent bond in
  the diatomic hydrogen molecule H2.
• The halogens such as chlorine also exist as
  diatomic gases by forming covalent bonds.
• The nitrogen and oxygen which makes up the bulk
  of the atmosphere also exhibits covalent bonding
  in forming diatomic molecules.

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Covalent Bond

• The number of shared pairs (covalent bonds) of
  electrons an atom forms. eg Hydrogen H needs 1
  additional electron
• Hydrogen bonds1 pair of e-'s shared between 2
  atoms - covalent bond.

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Hydrogen

• Bonding pairs of electrons orbit both nuclei -
  attracts both nuclei - provides bonding force.
• A Hydrogen molecule consists of 2 covalently
  bonded hydrogen atoms which have no tendency to
  bond further (both have achieved a stable outer
  shell).
• Each molecule exists independently.

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Single Covalent Bond
Single Bond - 1 shared pair of electrons.
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Covalent Bond Lewis Structure
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Hydrogen Animation
http//bio.winona.msus.edu/berg/ANIMTNS/hydrgnan.g
if
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Covalent Molecular Compounds

• Explanation
• No mobile charged particles
• Molecules not charged
• Electrons tightly bound to atoms or shared by
  atoms in covalent bonds.
• During melting/boiling, molecules become
  separated.
• Forces of attraction between molecules are weak
  and little thermal energy is required to separate
  them.
• Soft.Molecules weakly attracted to each other and
  are easily displaced.

Property Do not conduct electricity.
Melting and boiling points low.
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Equal Electronegativity

• In covalent bonds, electron pairs are shared
  equally between atoms of equal electronegativity.

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Differing Electronegativity

• When atoms in a covalent bond have differing
  electronegativity . . .
• the atom with the higher electronegativity has
  ?50 of the shared pairs of electrons
• the atom with low electronegativity has ?50 of
  the shared pairs of electronegativity.
• The atom tending to gain electrons acquires a
  slight negative charge
• The atom tending to lose electrons acquires a
  slightly positive charge
• The bond is POLAR.

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Polar Bonding
http//bio.winona.msus.edu/berg/ANIMTNS/pcbondan.g
if
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Polar Covalent Bonds
d
d-
H
Cl
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Analogy to Population