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					        Monday, October 29, 2012
Warm-up (10/29/12)             Agenda
  – What element is this
    electron configuration
    for                        1. Warm-up/Stamp HW
1s22s22p63s23p64s23d10         2. Review Warm-up
4p65s24d105p66s24f145d4        3. Notes: Periodic
  – Write the noble gas           Table/Trends
    configuration for the
    element above.
  – Draw the orbital           HW: p. 167 # 22-23, 25-31
    diagram for nickel (Ni).
                 The Periodic Table
                     Dimitri Mendeleev
• Developed by _________________ according
     properties of the elements
  to ___________________.

• Rows = ______________
            periods
• Columns = ________________
              Groups/families

• Elements in the same _______ react the
                            family
  same because they have the same
   number of valence electrons
  _____________________

• Valence Electrons -
   Electrons in the highest (outermost) energy level.
   Carbon has 4 valence electrons.
              Group/Family Names
•   Group 1 ________________________
             Alkali Metals

•   Group 2 ________________________
             Alkaline Earth Metals

•   Group 17 (7A) ________________________
                      Halogens

•   Group 18 (8A) ________________________
                      Noble Gases

•   Group 3-12 ________________________
                 Transition metals

•   Group 13-16 ________________________ etc.)
                    Name of 1st element (boron family, carbon family,

•   Named Rows ________________________
                     Lanthanide and Actinide Rows
                            Periodic Trends
Atomic Radius
The atomic radius is the average
distance from the nucleus to the outer
electron cloud.

1) Atomic Radius increases as you go down a
group.
• Why?
   Atoms increase levels of electrons as they
   increase in mass.
2) Atomic Radius decreases as you go across a
group.
• Why?
   In the same electron energy level, the increase
   in # of protons pulls the electrons closer.
                     Periodic Trends
Ion Size
Ions have gained or lost electrons, so their sizes
are different from neutral atoms.
Cations:
    Positive (+) ions,
    Smaller than neutral atom.
    They have LOST electron(s).


Anions:
    Negative (-) ions,
    Larger than neutral atom.
    They have GAINED electron(s).
                         Periodic Trends
Ionization Energy
The ionization energy is the
energy needed to remove an
electron from an atom.

1) Ionization Energy decreases as you go down a group.
• Why?
    Electrons are farther away from the nucleus in big atoms

2) Ionization Energy increases as you go across a group.
• Why?
    Electrons are held more tightly with increasing atomic #.
                        Periodic Trends
Electronegativity
The electronegativity is the
tendency for atoms to attract
electrons.

1) Electronegativity decreases as you go down a group.
• Why?
   Electrons are farther away from the nucleus in big atoms.

2) Electronegativity increases as you go across a group.
• Why?
   Electrons are held more tightly with increasing atomic #.
        Tuesday, October 30, 2012
Warm-up (10/30/12)        Agenda

a. How many valence
   electrons do           1. Warm-up/Stamp HW
   elements in the          1. P. 167 #22-31 (not 24, 26)
   halogen family have?   2. Review Warm-up/HW
                          3. Grade Unit 2 Notebook
b. What type of ion
                          4. WS: Noble Gas Envy
   (with what charge)
   will these atoms
   typically form?        HW: Finish Worksheet
        p. 167 # 22-23, 25, 27-31
                             One half the distance between the nuclei
22. a. What is meant by      of two bonded identical atoms.
    atomic radius?
                             The atomic radius decreases across
    B. What trend is         a period (from left to right).
    observed among the
    atomic radii of main-
    group elements across
    a period?
    C. Explain this trend.   In the same electron energy level,
                             the increase in # of protons pulls
                             the electrons closer.
        p. 167 # 22-23, 25, 27-31
                             The atomic radius generally increases
23. a. What trend is         down a group.
    observed among the
    atomic radii of main-
    group elements down
    a group?
    b. Explain this trend.   Down a group, elements add
                             another energy level per period,
                             making a larger atom.
        p. 167 # 22-23, 25, 27-31
                               The ionization energy increases across a
25. a. How do first            period and decreases down a group.
    ionization energies of
    main-group elements
    vary across a period
    and down a group?
                               Across a period, the increasing nuclear
    B. Explain the basis for   charge attracts electrons in the same
    this trend.                energy level more strongly and makes
                               them difficult to remove.

                               Down a group, the electrons to be
                               removed are farther from the nucleus in
                               increasingly higher energy levels and are
                               more easily removed.
        p. 167 # 22-23, 25, 27-31
                              A cation is a positive ion, and an anion is
27. a. Distinguish            a negative ion.
    between a cation and
    an anion.
    B. How does the size      Cations are always smaller than the
    of each compare with      atoms from which they are formed;
                              Anions are always larger.
    the size of the neutral
    atom from which it is
    formed?
        p. 167 # 22-23, 25, 27-31
28. a. What are valence   Valence electrons are atomic electrons
                          available to be lost, gained, or shared in
    electrons?            the formation of chemical compounds.


   b. Where are such      Valence electrons are located in
   electrons located?     an atom’s outermost energy level.
            p. 167 # 22-23, 25, 27-31
29. For each of the following groups,
indicate whether electrons are more
likely to be lost or gained in compound
formation and give the number of such
electrons typically involved.



  A. Group 1      Lost, 1         D. Group 16    Gain, 2

  B. Group 2      Lost, 2          E. Group 17   Gain, 1

  C. Group 13     Lost, 3          F. Group 18   Neither lost nor gained, 0
        p. 167 # 22-23, 25, 27-31
30. a. What is           Electronegativity is the ability of an atom
                         in a chemical compound to attract
    electronegativity?   electrons from other atoms.


   B. Why is fluorine
                         Fluorine is the most electronegative
   special in terms of   element and is arbitrarily assigned an
   electronegativity?    electronegativity of 4.0.
        p. 167 # 22-23, 25, 27-31
                             Group 17, most electronegative
31. Identify the most- and
                             Group 1, least electronegative
least-electronegative of
elements in the periodic
table.
    Wednesday, October 31, 2012
Warm-up (10/31/12)   Agenda

a. none              1. Stamp HW
                     2. Review HW
                     3. Unit 3 Quiz 1

                     HW: None
Thursday, November 1, 2012
             Agenda

             1. Stamp HW (again)
             2. Finish quiz?
             3. Notes: Chemical
                Bonding

             4. HW: Yes…
       Notes: Chemical Bonding
• Question: Why do atoms form chemical
  bond?
• Answer… • The goal of atoms in any
            chemical bond is to attain noble
            gas electron configuration.
            (Octet rule; 8 valence e-)

Exceptions to this rule: H, He, Li, Be, B
         Exceptions to this rule
• H, He, Li, Be, B
           II. Lewis Structure
• A ________________ is a way to symbolically
    Lewis dot structure
                 valence electrons
  represent the _______________ of atoms.

• Each ______ represents
        dot
  one electron

        line
• Each ______ represents two
  shared electrons in a
  covalent bond.
How to draw an atoms Lewis Structure
• A. Determine how many valence electrons.
  – How??
• B. Imagine there is a square around the atom.
• C. Add dots to each side of the square before
  doubling up.
  – The number of dots should be the same as the
    number of valence electrons.
  – (Hund’s Rule! Firsts before seconds)
     Practice!

Al

S
     III. Two Main Types of Bonding
Two main types:
  – Covalent      Electrons shared between atoms
    Bond          Occurs between nonmetals.
                  Examples: CO2, H2O, CH4




  – Ionic Bond    Electrons lost or gained by atoms

                  Occurs between a metal and a nonmetal.

                  Examples: NaCl, MgO, LiF, CaCl2
          IV. Covalent Bonding
• Example: A Chlorine Molecule
• Each Cl atom wants to _________ to become
                             gain 1 e-
  stable (like a noble gas).
• If each atom __________, they will have 18 e-
                  share an e-
  like argon and have a full octet in its valence
  shell!
Covalent Bonding
               Diatomic Molecules
Elements that exist in pairs if not paired with something else.
  Remember: H2O2F2Br2I2N2Cl2 (HOFBrINCl)
Covalent Bonding
        Friday, November 2, 2012
Warm-up (11/2/12)          Agenda
a. Order the following
   elements from largest   1. WUQ/Stamp HW
   to smallest atomic
   radius: K, As, Mn, O,   2. Review WUQHW
   He, Fr                  3. Notes: Covalent Lewis
                              Structure
a. Which element is the
   most electronegative
   element in the whole    HW: Covalent Lewis
   periodic table?
                           Structure

				
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