Dmitri Mendeleev: Developed the first Periodic Table

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• Dmitri Mendeleev Developed the first Periodic
  Table
• Mendeleevs Periodic table - based on chemical
  properties of the elements
• Mendeleev noticed that properties such as
  chemical reactivity increased in a repeated
  (periodic) manner
• Ordered the elements by atomic mass

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• Mendeleev left spaces when properties of
  elements above and below did not match
• Mendeleev predicted properties of unknown
  elements
• When the unknown elements were discovered, it was
  found that Mendeleevs predictions were correct!

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• Periodic Table
• The periodic table is made up of rows and columns
• Elements are identified by chemical symbols
• First letter is capitalized (e.g. N)
• If a second letter is present -lower case
• (e.g. Na)
• A row is called a period
• A column is called a group or family

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staircase
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Rows are called Periods
Periods 1 to 7
staircase
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METALS

• Shiny
• Malleable
• Good conductors

elements to the left of the staircase
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Non-Metals elements to the right of the
staircase

• Dull
• Brittle
• Poor conductors

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Metalloids (semi-metals) elements which border
the staircase

• Shiny or dull
• Brittle
• Semi-conductors
• E.g. Silicon

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• silicon is used to make transistors, solar cells,
  and microchips

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Alkali Metals
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Alkali Metals (Group IA)

• Most reactive metal family
• Violent reactions with water
• Soft, silver-white, shiny

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• Alkali Metal Explosions

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Alkaline Earth Metals
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Alkaline Earth Metals (Group IIA)

• Silvery-White Metals
• Second most reactive metal family
• Many are found in rocks in the earths crust

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Halogens (Group VIIA)
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Halogens (Group VIIA)

• Most reactive non-metal family
• React with Group IA very easily

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Noble Gases (Group VIIIA)
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Noble Gases (Group VIIIA)

• Gases at room temperature
• Normally unreactive (inert)