Mendeleev

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Mendeleev

• Arranged the 70 known elements at the time in
  columns in order of increasing atomic mass. He
  then arranged the columns so that the elements
  with the most similarities were side by side.
• Created the first Periodic Table.

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Mendeleevs First Periodic Table
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Periodic Table an arrangement of the elements
according to the similarities in their properties

• Mendeleev was even able to predict the physical
  and chemical properties of the missing elements.
  (When these elements were discovered, they were
  found to have properties similar to those
  predicted)

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Moseley

• Moseley later arranged the elements in a table by
  order of atomic number instead of atomic mass

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The Periodic Table

• Periods
• horizontal rows are called periods
• There are seven periods
• The properties within a period change as you move
  across it from element to element
• If you move from one period to the next, the
  properties within the period repeat
• All elements in a period have the same of
  atomic orbitals
• Ex. First period (1 orbital)
• Second period (2 orbitals)

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The Periodic Table

• Groups or Families
• Vertical columns of elements in the PT
• The elements in any family of the PT have similar
  physical and chemical properties
• Have the same number of electrons in their outer
  orbitals (valence electrons)
• Hydrogen has characteristics of both group 1 and
  7
• Helium needs only two electrons in its outer
  shell to be filled (happy).
• Families have specific names associated with them
  because they have similar physical and chemical
  properties

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75 of Elements are Classified as Metals

• Properties of metals
• conduct electricity
• high luster
• ductile (able to be drawn into wires)
• malleable (able to be beaten into thin sheets
• elements on the left and center of the PT are
  metals

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Groups or Families divided into 8 groups
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Group 1 Alkali Metals
Li

• very reactive
• never found free in nature
• react readily with water
• shiny, light in weight

Na
K
Rb
Fr no images of Francium available
Cs
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Group 2 Alkaline Earth Metals

• reacts with oxygen
• not as reactive as Group 1, makes bonds very
  easily

Ca Calcium
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• Group 3
• Boron group, made of metals and metalloids
• Group 4
• Carbon group, made of Metals and Nonmetals
• Group 5
• Nitrogen group, elements form an oxygen or sulfur
  compound
• Group 6
• Oxygen group, Nonmetals

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Group 7 Halogens

• elements combine violently with alkali metals to
  form salts
• Halogens mean salt-forming
• Highly reactive
• 7 electrons in outer shell, only need one to be
  happy

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Group 8 Noble Gases

• have full outer shells with 8 electrons (except
  for He)
• least reactive group
• not very abundant
• Neon in advertisement signs
• Argon light bulbs
• Helium balloons
• Xenon used in headlamps (ultra bright-blue)

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Metalloids

• Stair step line that distinguishes metals from
  non-metals. Drawn from between Boron Aluminum
  to the border of Polonium Astatine
• Boron
• Silicon
• Germanium
• Arsenic
• Antimony
• Tellurium
• Polonium

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Transition Metals

• All elements between Group 2 and Group 3,
  including the inner transition metals (lanthanide
  actinide series)
• Able to put more than 8 electrons in their next
  to last shell
• Can use the two outermost orbitals to bond with
  other elements
• Actinide series are radioactive and some cannot
  be found in nature
• Lanthanide series can be found naturally on earth

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Transition Metals
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Periodic Table Review

• What criteria did Mendeleev use to construct his
  PT?
• arranged elements by order of atomic number
• arranged elements by order of atomic mass

• What criteria did Moseley use to reconstruct the
  PT?
• arranged elements by order of atomic number
• arranged elements by order of atomic mass

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Review

• A period on the Periodic Table
• is represented by vertical columns of elements
  which have similar physical properties and
  chemical properties
• is represented by horizontal rows of elements and
  the properties of the elements change as you move
  from element to element

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Review

• A Family/Group on the Periodic Table
• is represented by vertical columns of elements
  which have similar physical properties and
  chemical properties
• is represented by horizontal rows of elements and
  the properties of the
• elements change as you move from element to
  element

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Review

• Identify each element as a metal, metalloid, or
  nonmetal
• gold
• silicon
• manganese
• sulfur
• barium

• Metal
• Metalloid
• Metal
• Nonmetal
• Metal

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Review

• Pick two elements that have properties similar to
  those of the element calcium
• Zn
• Mg
• Cr
• Sr