CH 19

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CH 19

• Elements and Their Properties

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Find your observations of elements from Wednesday
9/30. (sulfur, aluminum, iron)

• N
• Which element(s)
• Were powdery or brittle
• Were not malleable
• Did not conduct electricity

• M
• Which element(s)
• Conducted Electricity
• Were shiny
• Were malleable (bendable)

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Properties of Metals

• Physical Properties
• Ductile (make wires out of it)
• Malleable (bendy/poundable)
• Conduct electricity
• Also
• Found on the left side of the periodic table.

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Metallic Groups

• (1) Alkali Metals Very, very reactive, 1
  valence electron
• (2) Alkali Earth Metals Very reactive, 2 valence
  electrons.
• (3-12) Transition Elements Often found
  uncombined. Can form colored compounds.

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Non Metals

• Brittle or powdery
• Not malleable , not ductile
• Do not conduct electricity

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Non-Metallic Groups

• Hydrogen (1?)
• smallest element, comes in pairs diatomic
• Halogens (17)
• Very reactive as elements, mostly diatomic gases,
  7 valence electrons.
• Fluorinemost chemically active of all elements
• Noble Gases (18) Noble Gas Balloons
• Do not react with other elements
• Very stable, 8 valence electrons.

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Mixed Groups

• Metaloids (semi-metals, semi-conductors)
• Along stair step line
• can form 2 kinds of bonds (ionic, covalent)
• Kind of shiny, kind of conductive, kind of
  brittle

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Carbon

• carbon allotropes
• Pure carbon comes in different forms or
  allotropes
• Pencil lead graphite
• Diamonds
• Buckyballs
• All pure carbon, but bonds are in different
  arrangements.

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Synthetic Elements, and trans-Uranium elements

• Smash large elements together at high speed.
• element 112
• Bombard Uranium (U) with neutrons can turn it
  into Neptunium.
• Plutonium can be changed to Americium
• Americium is used in smoke detectors.

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Why synthetic?

• Clock, car engine
• To understand how something works, you may want
  to watch it being built, and/or watch it being
  destroyed.