GROUP 17 BONDING the HALOGENS

1
GROUP 17 BONDINGthe HALOGENS

• Bond mainly by ionic bonding to become 1- ions
  with noble gas configurations.
• The ions are isoelectronic to the noble gas of
  the SAME period, which is the kernel of that
  element.
• High electronegativity and High ionization energy
  causes an electron to be gained, completing the
  p sublevel and the outer shell octet.
• As you read down the group, electronegativity,
  ionization energy and nonmetal reactivity
  DECREASE, atomic radius INCREASES. See concept
  map.
• All negative ions are larger than the neutral
  atom from which they are derived, due to a gained
  electron.

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EXAMPLES

• The configuration of Neon

1s2??
2s2 ?? 2p6 ?? ?? ??

• The configuration of FLOURINE (ground)

1s2??
2s2 ?? 2p5 ?? ?? ?_
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AFFINITY and REDUCTION

• The addition of an electron is called ELECTRON
  AFFINITY, the energy that is evolved to do so is
  called AFFINITY ENERGY. This process is
  exothermic energy releasing, the energy must
  have a sink that will absorb it..

• In the diagram below, the following is important
• The electron gained will most likely be obtained
  by from a metal.
• The resulting ion is isoelectronic to the noble
  gas of the same period.
• AFFINITY ENERGY is released.

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