THE PERIODIC TABLE

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THE PERIODIC TABLE
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The History of the Table

• Dobereiner (early 1800s) triads.
• Newlands (1865) atomic mass and octaves.
• Meyers and Mendeleev (1869) based on atomic
  mass and columns with similar properties.
• Moseley (1913) based on atomic number.

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The Periodic Law

• When elements are arranged in order of increasing
  atomic number, their physical and chemical
  properties show a periodic pattern.

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The Organization

• Groups or families and periods.
• Family names.
• Groups similar properties.
• Vertical columns vs. horizontal rows.
• Metals (transition inner transition),
  nonmetals, and semi-metals.
• Malleability vs. ductility.

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Electron Configuration

• Electrons in the highest principle energy level
• Outermost electrons
• Valence electrons
• Elements in a group have similar properties
  because they have valence electrons in a similar
  configuration.
• Abbreviated electron configuration using the
  noble gas inner core.
• Four blocks (s, p, d, and f).

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• The shape of the periodic table is a result of
  the way electrons fill the orbitals of different
  energy levels.

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Periodic TrendsA systematic variation in the
properties of elements going down a group or
across a period.

• Atomic radius.
• Ionic radius.
• Ionization energy.
• Successive ionization energies.
• Electronegativity.

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Atomic Radius

• The distance from the center of an atoms nucleus
  to its outermost electron.
• Atoms get larger going down a group.
• Atoms get smaller moving from left to right
  across each period.
• Why?

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Ionic Radius

• Atom loses electrons positive ion smaller.
• Atom gains electrons negative ion larger.
• Ion trend (Left vs. Right side).

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Ionization Energy

• The energy needed to remove one of an atoms
  electrons.
• Measure of how strongly an atom holds onto its
  outermost electron.
• Ionization energies decrease as you move down a
  group.
• Ionization energies increase as you move from
  left to right across a period.
• Opposite the atomic radius trends.

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Successive Ionization Energies

• Increases for each electron removed.
• Large jump for noble gas inner core.

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Electronegativity

• Reflects the ability to attract electrons in a
  chemical bond.
• Related to its ionization energy and electron
  affinity.
• Increases as you move from left to right and
  decreases as you move down.

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In Generalas you move down a family
metals melting points
boiling points Decreases as metals get
heavier nonmetals melting points
boiling points Increases as nonmetals get
heavier