The Periodic Table

1
The Periodic Table
2
REVIEW

• All atoms of a specific element are alike
• All atoms of different elements are different
• 90 naturally occurring
• Arranged on Periodic Table to show trends

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A Brief History of the Periodic Table

• Mendeleev Moseley - Seaborg

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Mendeleev (1869)

• Thought pattern must exist between all elements
• Organized table by...
• ATOMIC MASS
• Elements in columns show similar properties
• Both physical and chemical!
• Predicted properties of missing elements

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Mendeleevs TABLE
His notes
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What he thought!

• I began to look about and write down the
  elements with their atomic weights and typical
  properties, analogous elements and like atomic
  weights on separate cards, and this soon
  convinced me that the properties of elements are
  in periodic dependence upon their atomic
  weights.
• Mendeleev, Principles of Chemistry, 1905, Vol. II
  as quoted at lthttp//www.aip.org/history/curie/pe
  riodic.htmgt.

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Definition

• What does PERIODIC mean?
• A repeating pattern
• Mendeleev left some spaces in his table because
  not all elements lined up according to atomic
  mass. He used info he knew about surrounding
  elements to PREDICT properties and masses of
  unknown elements.
• How about that!

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Mendeleevs Predictions vs. Actual Properties of
Element 32
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Moseley (c. 1914)

• rearranged table by ...
• ATOMIC NUMBER
• determined atomic number of elements by using
  x-rays to determine number of protons in element

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Moseleys work
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Seaborg (1944)

• rearranged Periodic Table with...
• Lanthanide and Actinide Series pulled
  out/separated from main Periodic Table
• discovered 10 new elements countless isotopes

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3DAlexanders Arrangement of Elements
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definition

• Periodic Law
• The physical and chemical properties of the
  elements are periodic functions of their atomic
  number

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definition

• Octet Rule
• The tendency of atoms to gain or lose electrons
  so they acquire eight electrons in their outer
  energy level

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Columns of Table groups or families

• Numbered 1 18
• Group numbers tell us the number of electrons in
  that elements outer energy level - the number
  in red
• Elements within the same family have similar but
  not identical properties

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definition

• Valence electrons
• electrons found in the outermost energy level
• use the group number (the number in red) to
  determine number of valence electrons

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NAMES to Know
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NAMES to Know

• Group 1
• Alkali Metals

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NAMES to Know

• Group 2
• Alkaline Earth Metals

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NAMES to Know

• Groups 3-12
• Transition Metals

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NAMES to Know

• Inner Transition Metals
• Lanthanide Series
• Actinide Series

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NAMES to Know

• Group 16
• Chalocgens

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NAMES to Know

• Group 17
• Halogens

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NAMES to Know

• Group 18
• Noble Gases

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Rows of Table periods

• 7 periods
• Period of energy shells in atom
• Properties are not alike within a period
• across each period (row), the chemical physical
  properties of elements change
• these properties are repeated in the next period
  (the row below)

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Periods 1 to 7
1
2
3
4
5
6
7
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Regions of the Periodic Table

• Metals - to the left of the stair-step line
• Non-Metals - to the right of the stair-step line
• Metalloids - along the stair-step line

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Regions of the table
One more!
NONMETALS
METALLOIDS
METALS
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Metals

• Found to LEFT of zigzag line on table
• Good conductors of heat electricity
• Malleable
• Ductile
• High melting points
• Shiny
• Tend to lose electrons
• ? forming cations

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Nonmetals

• Found to RIGHT of zigzag line on table
• Plus Hydrogen (atomic number 1)
• Poor conductors of heat electricity
• Brittle when solid
• Dull
• Low melting points
• Tend to gain electrons
• ? forming anions

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Metalloidsaka Semi Metals

• Found along both sides of zigzag line
• Properties of both metals nonmetals
• Okay conductors of heat electricity
• Shiny or dull