The Periodic Table by mikesanye

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									The Periodic Table
       Taking a Closer Look
• Elements can be classified as:
  – Metals
  – Non-Metals
  – Metalloids
                    Metals
•   Can be moulded and shaped
•   Can be made into a wire  ductile
•   Good conductors of heat and electricity
•   Usually have high melting points
                Non-Metals
•   Usually brittle
•   Poor conductors of heat and electricity
•   Dull surface (if solid)
•   Lower melting point
                 Metalloids
•   Brittle and not ductile
•   May conduct electricity
•   Poor conductors of heat
•   Solids with very high melting points
               Table of Properties
             State (at room Appearance      Conductivity   Malleability &
             temp.)                                        Ductility


Metals          Solid                                      Malleable &
               EXCEPT:         Shiny           Good         Ductile
               Mercury
Non-         Gas OR Solid
Metals        EXCEPT:           Dull            Poor       Brittle & Not
               Bromine                                       Ductile
Metalloids                                  Electricity   Brittle & Not
                 Solid      Shiny or Dull     maybe          Ductile
                                            Heat  poor
Mercury (metal that is   • Bromine (liquid non-
        liquid)                  metal)
       Families of Elements
• Just like you and your family the elements
  are different but share similar
  characteristics
• That is why the periodic table can be
  broken down into “families” of elements

    Turn to page 220 in your text books
 Dimitri Mendeleev (1834-1907)
• The organization of the elements
  into the Periodic Table is
  credited to Mendeleev, a Russian
  Chemist

• His work was accomplished at
  a time when little was known
  about the atomic structure of matter

• Based on chemical and physical properties, he was able
  to group them into families, an arrangement that has
  become known as the Periodic Table
            An Eye for Pattern
• Mendeleev knew the properties of the elements and
  listed them on his element cards

• After he placed them in order of atomic mass,
  he noticed patterns

• The properties of a particular element would
  be repeated by a heavier element

• He began to rearrange his element cards
  placing those elements with similar properties
  into columns always increasing mass order
              Periodic Law
• Mendeleev stated that:
  – When the elements are arranged in order of
    increasing atomic mass there is a periodic
    repetition of properties
     Predicting New Elements
• The genius of Mendeleev is shown by the
  use of blank spaces in his periodic table
• Spaces were left in a row because to fill
  the spot would break the pattern of the row
        Predicting the Elements
              Continued..
• Mendeleev suggested that there was an element
  (although not yet discovered) to fill the spot
• Two example, Gallium (atomic #31) and
  Germanium (atomic #32) are famous for being
  discovered shortly after Mendeleev’s prediction
  of their existence
• Not only was Mendeleev able to predict their
  existence, but he was also able to predict their
  properties
   The Modern Periodic Table
• Through Mendeleev’s predictions and
  ability to see patterns the modern Periodic
  Table was developed

• Vertical columns = GROUPS (there are 18
  groups or families
• Horizontal rows = PERIODS (there are 7
  periods)
Periods – Horizontal rows on the periodic table
Groups – Vertical columns on the periodic table
                       Groups
• Each group, on the Periodic Table, has similar
  characteristics:
  – Outer electrons
  – Physical properties
  – Chemical Properties

• The group names are:
  –   Alkali Metals
  –   Alkaline Earth Metals
  –   Halogens
  –   Nobel Gases
  –   Hydrogen

								
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