Ch. 4 - The Periodic Table

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History

• Ch. 4 - The Periodic Table

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A. Mendeleev

• Dmitri Mendeleev (1869, Russian)
• Organized elements by increasing atomic mass.
• Elements with similar properties were grouped
  together.
• There were some discrepancies.

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Mendeleevs Table
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A. Mendeleev

• Dmitri Mendeleev (1869, Russian)
• Predicted properties of undiscovered elements.

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B. Moseley

• Henry Mosely (1913, British)
• Organized elements by increasing atomic
  number.
• Resolved discrepancies in Mendeleevs
  arrangement.

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Periodic Table

• The periodic table is an arrangement of the
  elements according to similarities in their
  chemical and physical properties.

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Groups or Families of Elements

• Vertical columns on the periodic table
• Similar physical properties
• Similar chemical properties

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Representative Groups (group A) on the Periodic
Table

• 1 2 13 14 15 16 17
  18

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Representative Groups

• Group 1 Alkali Metals
• Group 2 Alkaline Earth Metals
• Groups 13-16
• Group 17 Halogens
• Group 18 Noble Gases

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Location of Some Groups

• 1 2 13 14 15 16 17 18

A l m k e a t l a i l s
A l k a l i n e
H a l o g e n s
I G n a e s r e t s
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B. Blocks

• Main Group Elements (representative elements)
• Transition Metals
• Inner Transition Metals

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• The group B are called the transition elements

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• Horizontal rows are called periods
• There are 7 periods

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Periods on the Periodic Table

• Horizontal rows from Group 1 to Group 18.
• Numbered 1, 2, 3, .
• Include
• representative elements (groups 1-2, 13-18) and
  transition elements (groups 3-12)

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Periods on the Periodic Table

• 1
• 2
• 3
• 4
• 5
• 6

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Learning Check

• A. Element in Group 17, period 4
• Br
• B. Element in Group 2, Period 3
• Mg
• C. Metals in Group 14
• Sn, Pb
• D. Nonmetals in Group 15
• N, P,

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A. Metallic Character

• Metals
• Nonmetals
• Metalloids

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Metals and Nonmetals

• Metals
• Located to the left of the stair-step line
• Shiny, ductile, malleable
• Good conductors of heat and electricity
• Nonmetals
• Located to the right of the stair-step line
• Dull and brittle
• Poor conductors, good insulators

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Metalloids or Semiconductors

• Semiconductors have intermediate electrical
  properties
• Conduct electricity better than nonmetals but
  not as well as metals
• Located along the stair-step line

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Learning Check
Specify metal (1) or nonmetal (2) for each

• A. sulfur
• B. chlorine
• C. sodium
• D. iron
• E. carbon
• F. silver

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2
1
1
2
1