The Periodic Table

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The Periodic Table
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Dmitri Mendeleev(1834 1907)

• He organized elements into the first periodic
  table
• He arranged elements by increasing atomic mass

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Henry Moseley(1913)

• He arranged elements according to atomic number
  rather than atomic mass
• The modern periodic table is arranged by atomic
  number

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Periodic Law

• The periodic law states that
• there is periodic repetition
• of chemical and physical
• properties of elements

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The Modern Periodic Table

• There are 18 groups (columns up and down)
• The group As (the tall columns) are called
  representative elements

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• The group Bs (the middle columns) are called
  transition metals

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• There are seven periods
• (rows across the periodic
• table)

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• Metals are to the LEFT of the
• zig-zag line (except hydrogen!)

Metals in yellow
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• Nonmetals are to the RIGHT of
• the zig-zag line

nonmetals in red
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Metalloids

• Metalloids are those elements ON the zig-zag line

Metalloids border the zig-zag line
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• Now . . .YOU fill in the
• chart using your book!

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Metals

• solid at room temperature
• shiny (have luster) and smooth
• good conductors of heat and electricity

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Metals

• malleable bendable (can be pounded into
  sheets)
• ductile - can be pulled
• into wires

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Metals

• react with acids
• mercury (Hg) is the only LIQUID metal

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Nonmetals

• generally gases or brittle, dull looking solids
  at room temperature
• poor conductors of heat and electricity
• Bromine (Br) is the only LIQUID nonmetal

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Metalloids

• sometimes called semimetals
• metalloids have properties of both metals and
  nonmetals

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Metalloids

• silicon and germanium are two of the most
  important metalloids (theyre used in computer
  chips and solar cells)