Properties of P-Block Elements Section 7.2

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					Properties of P-Block
    Section 7.2

• Describe and compare properties of p-
  block elements.
• Define allotropes and provide examples.
• Explain the importance of organisms of
  selected p-block elements.
Where is the P-Block of Elements?
  The Elements of the P-Block
• The elements of the p-block have large
  variations in their characteristics.
• Remember that some of the elements are
  metals, some metalloids, and some are
  Group 3A: The Boron Group
• Remember to highlight your periodic table.
• Always found in combination with other
  elements in nature.
• Most elements in the group form an ion
  with a 3+ charge: Thallium does not.
               Boron (B)

• Lightest member.
• Least representative of the group.
• Boron acts more like Silicon and has a
  diagonal relationship.
• Boron is used in laboratory glassware
  since it will not shatter in extreme
                                        B Cont.
• Boron is extracted from a compound
  called borax.
• Found in California’s Mojave Desert.,%20Mojave%20Desert,%20California.jpg
                                Aluminum (Al)

 • Most abundant metal.
 • Third most abundant element on Earth.
 • Al is removed from bauxite (Aluminum
       – Requires a great deal of energy to remove Al.
       – Recycling uses only 5% of the energy
         required to initially extract Al.
                    Al Cont.
• Uses include:
  – Aluminum Oxide:
    • Abrasives.
    • Strengthen ceramics.
    • Heat-resistant fabrics.
                                            Al Cont.
• Rubies and Sapphires are crystals of
  Aluminum oxide.
• Aluminum sulfate (Alum) is found in


                                           Gallium (Ga)
   • Can melt in your hand.
   • Used in semiconductor chips in calculators
     and solar panels.
   • Used in lasers (blue light).
 Group 4A: The Carbon Group
• Carbon is not a representative element of
  this group.
• This group has metals, metalloids, and
  non metals.
               Carbon (C)
• One of the most important elements on
• Carbon forms different compounds:

  – Mineral – element or inorganic compound that
    is found in nature as solid crystals.
  – Ore – a material from which a mineral can be
    removed at a reasonable cost.
                    C Cont.
• Examples of Carbon:
  – Diamond
    • Hardest known material.
  – Graphite
    • Extremely soft material.
    • Used as a lubricant.

    Allotrope: forms of an element in the same
     physical state; solid, liquid, gas, that have
     different structures and properties.
                Graphite vs. Diamond
                Silicon (Si)
• Computer chips, solar cells.
• Most often found as silicon dioxide: silica.
  – Quartz crystals.
  – Sand.
  – Glass.

        Lead (Pb) and Tin (Sn)
• Lead is toxic.
  – Old uses:
     • Eating utensils.
     • Paint and Pipes.
• Tin is a soft metal.
Group 5A: The Nitrogen Group
• 5 Valence electrons.
• Wide varying properties.
                     Nitrogen (N)
• Colorless, odorless, fairly unreactive.
• 78% of Earth’s atmosphere.
• Must be “fixed” to be used by most
  – Bacteria
  – Lightning

                Ammonia NH3
• Ammonia is used to make many products
  – Etch metal plates.
  – Cleaning products.
  – Dyes.
  – Fertilizers.

                      TNT and Nitroglycerin
• Extremely unstable.
                                                      Phosphorous (P)
                                          • Three allotropes:
                                            – White

                                            – Red
                                            – Black

                         P Cont.
• Found in fertilizers.
• Can be harmful to the environment in algal

 Arsenic (As), Antimony (Sb), and
           Bismuth (Bi)
• Less abundant elements.
• Some of the oldest known elements.
• Bismuth is in Pepto Bismol.

 Group 6A: The Oxygen Group
• Six valence electrons.
• Act as nonmetals.
• Gain two electrons to form an ion with a 2-
• May share two electrons to gain stability.
  – O2
                    Oxygen (O)
• Two allotropes:
  – Ozone: O3 (g)
  – Oxygen: O2 (g)

                O Cont.
• O is 21% of Earth’s atmosphere.
• Produced by plants.
• Forms to oxides with C.
  – CO
  – CO2
                       Sulfur (S)
• Ten allotropes.
• Sulfur dioxide preserves fruit.
• Sulfur dioxide reacts with water vapor to
  produce acid rain.

                              S Cont.
• Sulfur vents.
• Start the food chain in the bottom of the
  ocean where there is no light.

            Selenium (Se)

• Found in fish, eggs,
• Prevents cell
• Inhibits cancer
• Locoweed absorbs
  Se. Too much is
                           Se Cont.
• Charged ions of selenium create the
  image of the item being copied.
• The ink sticks to the image.

    Group 7A: The Halogens
• Commonly called salts formers.
• All but At share the following
  – Reactive nonmetals.
  – 7 valence electrons.
  – Share or gain 1 electron.
  – Form ions with a 1- charge.
                        Fluorine (F)
•   Lowest atomic number.
•   Most electronegative element.
•   Most active of all elements.
•   Reacts will all but three elements!

                                                          F Cont.
     • Fluoride is added to drinking water and
       toothpastes to improve dental health.
     • Coats nonstick cookware.
                     Chlorine (Cl)
• Also very reactive.
• Disinfectant.
• Color remover.

                                                                                                         Cl Cont.
                                                                                • Bleach.

                                                                                • Hydrochloric acid in stomach.
                                                                                • PVC (polyvinyl chloride) pipe.

   Bromine (Br) and Iodine (I)
• Not as many commercial uses as other
• Photographic film.
• Iodine: Healthy thyroid gland.
  – Disinfectant.

       Group 8A: Noble Gases
•   Colorless and unreactive.
•   Last to be discovered.
•   Stable electron configurations.
•   8 valence electrons.
                  Helium (He)
• Lightest noble gas.
• Blimps, airships, and balloons.
• Deep sea divers mix He with O.
  – He replaces N and prevents “bends.”

                       Neon (Ne)
• Used in light displays.
  – Argon (Ar) emits blue.
  – He emits pale yellow.

     Argon (Ar) and Krypton (Kr)
•   Ar is 1% of Earth’s atmosphere.
•   Ar is most abundant noble gas.
•   Ar is used in welding.
•   Both are used in light bulbs.

          Your Assignment
• Create a neon sign using different colors.
• Identify the noble gases that are
  responsible for the colors.
          Your Assignment
• Create flashcards for the elements we
  discussed in this lesson.

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