Valence%20Electrons

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Valence Electrons
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Valence

• Valence electrons are the electrons that are
  involved in chemical bonding.
• They have the highest amount of energy and are
  found in the outermost electron shell, furthest
  from the nucleus.
• The electron dot diagram shows the chemical
  symbol surrounded by the valence electrons.

dot diagram for neon
dot diagram for phosphorous
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Trading Electrons

• Chemical change involves trading valence
  electrons.
• Atoms are stable when they have 8 valence
  electrons.
• To become stable, atoms may either lose, gain or
  share electrons to form a chemical bond a force
  of attraction between two atoms as a result of a
  rearrangement of electrons.

Not balanced. Needs ___ electrons?
Balanced with 8.
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Whats your Valence?

• Hydrogen is grouped with the metals even though
  it is a nonmetal because it has _____ valence
  electron.
• group 1 (alkali metals)
• 1 valence electron
• group 2 (alkaline earth metals)
• 2 valence electrons
• group 13
• 3 valence electrons
• group 14
• 4 valence electrons

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• 1. What are valence electrons and what do we use
  to represent them?
• 2. What role do valence electrons play in the
  formation of compounds from elements?
• 3. How do the properties of elements change as
  you move across the periodic table from left to
  right, and what does this have to do with valence
  electrons?
• 4. Draw an electron dot diagram and atomic model
  for
• nitrogen, b) magnesium c) helium d)sulfur

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Valence continued

• group 15
• 5 valence electrons
• group 16
• 6 valence electrons
• group 17 (the halogens)
• 7 valence electrons
• group 18 (noble gases)
• 8 and are stable and unreactive as a result
• groups 3-12 (transition metals)
• 2,3, or 4 valence electrons

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More Practice

• Draw electron dot diagrams for
• magnesium, chlorine, potassium, krypton, carbon

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Practice!

• Draw electron dot diagrams for the following
  elements
• Calcium, oxygen, silicon, argon