Valence Electrons

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Valence Electrons
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The Octet Rule

• Atoms are most stable when they have a full shell
  of electrons in the outside electron ring,
  usually 8.

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How to determine the valence electrons

• By the group the element belongs to.

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Group 1 (Alkali Metals) Elements

• Have one electron in the outside shell
• They all have a valence of 1
• Will lose one and only one electron, that single
  outside electron to become a single positive ion
  with a full electron shell of eight electrons
• Lithium Sodium

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Group 2 (Alkaline Earth) Elements

• Have two electrons in the outer shell
• Have a valence of 2
• Can lose two electrons to become 2 ions
• Beryllium Magnesium

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Transition Elements, Lanthanides, and Actinides
Metals

• Many of them have varying valences because they
  can trade around electrons from the outer shell
  to the inner subshells that are not filled.
• They sometimes appear to violate the octet rule.

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Group 3 Elements (Boron)

• Have three outer shell electrons
• Have a valence of 3
• Boron Aluminum

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Group 4 Elements (Carbon)

• Carbon and silicon are non-metals because it is
  difficult to lose the entire four electrons in
  the outer shell, therefore they share electrons
  covalently
• Carbon

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Group 5 Elements (Nitrogen)

• Nitrogen and phosphorus are non-metals. They
  tend to gain three electrons to make an octet or
  bond covalently
• Nitrogen

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Group 6 Elements (Oxygen)

• Oxygen and sulfur tend to either gain 2 electrons
  or bond covalently.
• -2 charge
• Oxygen Sulfur

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Group 7 Elements (Halogens)

• Have seven electrons in the outer shell
• Can gain one electron to become a 1 ion
• Could make a covalent bond
• Are diatomic gases due to the strong tendency to
  bond to each other with a covalent bond.
• Fluorine Chlorine

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Group 8 Elements (Noble gases)

• Have a full octet in the outer shell
• Do not naturally combine chemically with other
  elements stable alone!
• Helium Neon

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The Charges of their ions

• Metals positive charges
• Non-Metals negative charges