Representative Elements

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Representative Elements

• Chapter 5 Section 2

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Representative Elements

• Remember that these are the elements in groups 1
  and 2 and 13 to 18
• Groups are classified by having similar
  properties

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Group 1 Alkali Metals

• Silvery Solids with low densities and low melting
  points
• Hydrogen is the only nonmetal in this group
• Tend to increase reactivity down the family
• Lithium (Li) is the least reactive and Francium
  (Fr) is the most reactive
• Contains Sodium (Na) and Potassium (K) too.

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Group 2 Alkaline Earth Metals

• Denser and Harder than Alkali Metals
• Have higher melting points
• Are reactive but not as reactive as Alkali metals
  
• Contains Beryllium (Be), Magnesium (Mg), Calcium
  (Ca), Barium (Ba), Radium (Ra)

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Group 13 Boron Family

• Are all metals except Boron
• Boron is a brittle, black metalloid
• Used to make a variety of products
• Such as Pots and Pans, Aluminum Cans, and
  Baseball Bats

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Group 14 Carbon Family

• A mixture of non-metals, metalloids and metals
• Contains Carbon a non-metal
• Contains Silicon and Germanium
• Tin and Lead are the heaviest metals in this
  group
• Lead is used to shield humans during X-Rays

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Group 15 The Nitrogen Group

• The top two elements are nitrogen and phosphorus,
  which are used by living things.
• Our bodies need nitrogen, but cannot get it
  simply from breathing nitrogen from the
  atmosphere, bacteria in soil must first convert
  the nitrogen into a form we can use (The nitrogen
  cycle)

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Group 16 The Oxygen Family

• The oxygen group contains oxygen and sulfur which
  are essential for life and used to manufacture
  many products.
• Sulfur is a solid, yellow nonmetal. Sulfur is
  used to manufacture sulfuric acid, which is used
  in fertilizers, detergents, synthetic fiber, and
  rubber.

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Group 17 The Halogen Group

• All of the elements except Astatine are
  nonmetals.
• The word Halogen means salt former for example
  Table salt chemical make up is NaCl, you may
  have already noticed that chlorine is a halogen.
  All halogens form similar salts
• Fluorine is most reactive, it combines with other
  elements easily. Chlorine is less reactive than
  fluorine but more reactive than bromine.

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Group 18 The Noble Gases

• They rarely combine with other elements, they are
  chemically inactive
• Helium is less dense than air so it is used in
  balloons. Hydrogen is also less dense, however
  Helium will not burn.
• Noble gases glow different colors when
  electricity is passed through them. Neon lights
  are not necessarily just neonunless of coarse
  they are reddish orange colored words.
• Helium, Argon, and Radon are all elements in this
  group
• Why would you not expect to combine magnesium and
  argon to produce a useful substance?

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An After thought.

• What are the characteristics of two
  representative element groups? How are elements
  in these groups used.