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Periodic Table Trends

Atoms &

the Periodic Table

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Essential Questions

  • How is the modern Periodic Table organized?

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  • Why do the elements in a group have similar properties?

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Vocabulary

Define the following vocabulary words:

  • Periodic Law
  • Periods
  • Groups/Families
  • Alkali metals
  • Alkaline Earth metals
  • Halogens
  • Noble gases
  • Metals
  • Metalloids
  • Nonmetals

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Periodic Table - History

Dmitri Mendeleev:

  • "Father of the Periodic Table"
  • Mid-1800's

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  • Organized table by elements’ chemical & physical properties

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  • Open spots in table = undiscovered elements
    • Correctly predicted their properties

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Periodic Table - History

Mendeleev came up with the “Periodic Law of the Elements.”

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Periodic Law – properties of elements change in a relationship to atomic number that repeats.

  • "Periodic" = repeating pattern

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Periodic Table - History

Henry Mosley:

  • Organized table by periods and groups.

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The original Periodic Table was organized horizontally by increasing mass & vertically by similar properties.

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Periodic Table

Groups (also called “Families”) - vertical columns

  • Same number of valence electrons

Organized by similar properties

Periods - horizontal rows

  • Same number of energy levels
  • Organized by increasing atomic number

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Periodic Table - Metals

Metals: left side of the Periodic Table

  • Most of the Periodic Table (75% of all elements)

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STAIRCASE

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Periodic Table - Metals

Characteristics of Metals:

  • Luster (shiny solids)
  • Malleable (bendable)
  • Ductile (stretchable)
  • Conducts electricity & heat well

STAIRCASE

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Periodic Table - Nonmetals

Nonmetals: far right of the Periodic Table

  • Most are gases at room temperature or brittle solids
  • Poor conductors of electricity & heat

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STAIRCASE

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Periodic Table - Metalloids

Metalloids: touching the “staircase” on the Periodic Table

  • Have properties of metals AND nonmetals

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STAIRCASE

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Periodic Table - States of Matter

The color of each symbol indicates the state of matter for an element.

Black = Solid Red = Gas Blue = Liquid

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Periodic Table

Name

Group

Properties

Valence Electrons

Alkali Metals

1

Soft and very reactive

1

Alkaline Earth Metals

2

React with acids to produce hydrogen

2

Halogens

17

React with metals to form salts

7

Noble Gases

18

Non-reactive

8

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Group 1 - Alkali Metals

  • Group: 1
  • Properties: Soft & very reactive
  • # of Valence Electrons: 1

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Color: dark green

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Group 2 - Alkaline Earth Metals

  • Group: 2
  • Properties: React with acids to produce hydrogen
  • # of Valence Electrons: 2

Color: light green

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Group 17 - Halogens

  • Group: 17
  • Properties: React with metals to form salts
  • # of Valence Electrons: 7

Color: yellow

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Group 18 - Noble Gases

  • Group: 18
  • Properties: Non-reactive ("noble" or "inert")
  • # of Valence Electrons: 8

Color: red

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Video: Noble Gases

Xenon is a noble gas that is six times more dense than air.

Helium is a noble gas that is six times less dense than air.

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Periodic Table - Summary

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Video Tutorial