Trends of the Periodic Table

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Trends of the Periodic Table

• CPS Chemistry

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Electron Configuration

• The chemical properties of an atom are largely
  determined by the arrangement of the electrons in
  its outermost ("valence") shell
• Although other factors, such as atomic radius,
  atomic mass, also contribute to the chemistry of
  the elements as atomic size increases.

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Electron Configuration







S block
P block
D block
F block


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Groups Periods

• Groups refer to columns, sometimes called
  families
• Periods refer to rows
• Main Group S P blocks
• D block Transition metals
• F block Lanthanide Actinide series

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Main Group Trends
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Atomic Radii

• The trend of how big an atom is
• Group bigger as you go down the group
• Period generally smaller as you go from
  left to right

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Ionization Energy

• Ionization energy is the amount of energy that it
  would take to remove one electron from a neutral
  atom
• Metals have low ionization energies and readily
  form positive ions.
• Nonmetals (due to small size, stronger nuclear
  charge, and many electrons in outer shells) have
  large ionization energies.
• Group Main Group elements energy generally
  decreases as it goes down a group.
• Period Main Group elements energy generally
  increases as you go across a period

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Electron Affinity

• Electron Affinity is the energy gained by a
  neutral atom when it gains a free electron,
  some atoms take electrons easily, others need
  to be forced. The Nobles will not take electrons.
  
• Group Generally, it is harder to add
  electrons as you go down a group
• Period Becomes more negative as you go across
  the period. (more ready to take electrons)

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Shielding Effect

• Outer shell electrons are shielded from the
  nuclear charge by interior shells.
• This shielding effect results in a larger cloud.

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Ionic Radii

• Ions are a non-neutral atoms, positive ions are
  called cations, negative are called anions
• Group Generally increases as you go down a
  group
• Period Generally decreases as you go across a
  period

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Valence Electrons

• Valence Electrons are the electrons that are
  involved in chemical bonding, either lost or
  gained.
• Group 1 1 valence electron
• Group 2 2 valence electrons
• Groups 3-12 1 or 2 valence electrons
• Groups 13-18 Valence electrons equal the group
  number minus 10
• ex. Group 14 has 4 valence electrons

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Electronegativity

• The ability of an atom in a chemical compound to
  attract electrons
• Coulombic attraction
• the positive-negative attraction which takes
  place when you have two charged particles in
  close proximity
• Group decreases as you go down the group, or
  remain the same
• Period increase as you go across, but there
  are some exceptions

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Oxidation States

• When 2 or more atoms combine, each atom tends to
  get a complete outermost shell holding 8
  electrons.
• The oxidation state is used to help identify how
  many electrons will be transferred or shared.
• A positive oxidation state indicates that the
  atom will lose electrons.
• A negative oxidation state indicates that the
  atom will gain or share electrons

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Trends of the d f block elements

• Properties of the d-block elements (all
  transition metals) vary less, and with less
  regularity than the Main Block elements.
• The d-level electrons are the ones that are
  responsible for the interactions with other atoms

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Trends d f blocks

• Atomic Radii
• Period Generally Decreasing across periods
• Ionization Energy
• Period Generally increase as you go across
• Group Increase as you go down
• Electronegativity
• d-block all range between 1.1-2.45
• F-block all range from 1.1 1.5