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ISOTOPIC NOTATION isotopes are atoms with the same number of

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ISOTOPIC NOTATION isotopes are atoms with the same number of Powered By Docstoc
					Transition Metals &
Valence Electrons
Chemistry 11
Transition Metals
   Do not form ions with noble gas configurations
   If they did, they would have to lose 4 or more
    electrons, and the energy needed to do this
    would be too high.
   These metals do form cations (“+” charged ion)
    with more than one charge (multi-valent)
   Electrons are first moved from the outer “s” and
    then inner “d” sublevels.
Example 1:

 25Mn          (18Ar)4s23d5
 Mn2+ loses 2 electrons from the “s”
  sublevel
 Mn2+          (18Ar)4s03d5
Example 2:

 26Fe          (18Ar)4s23d6
 Fe2+ loses 2 electrons from the “s”
  sublevel
 Fe2+          (18Ar)4s03d6
 Fe3+          (18Ar)4s03d5
Valence Electrons
 Are the electrons in the highest occupied energy level
  of an element’s atom.
 Are usually the only electrons used in the formation of
  chemical bonds.
Note:
  Many of the similar chemical properties of elements
  in the same group (vertical column) are related to the
  number of “s” and “p” electrons in the highest
  occupied energy level. These electrons are valence
  electrons.
Example 1: Sodium

 11Na

 1s22s22p63s1

 Highest energy level = 3
 Single “s” electron

 No “p” electrons for this element

 Na has 1 valence electron
Example 2: Phosphorus

 15P

 1s22s22p63s2 3p3

 Highest energy level = 3
 Two “s” electrons

 Three “p” electrons

 5 valence electrons
Example 3: Potassium
 19K

 Electron Configurations
 1s22s22p63s2 3p6 4s1

 Highest energy level = 4

 1 valence electron
Example 4: Carbon
 6C

 Electron Configuration
 1s22s22p2

 Highest energy level = 2

 4 valence electrons
Example 5: Magnesium
 12Mg

 Electron Configuration
 1s22s22p63s2

 Highest energy level = 3

 2 valence electrons
Example 6: Oxygen
 8O

 Electron Configuration
 1s22s22p4

 Highest energy level = 3

 6 valence electrons
Electron Configurations & Periodicity
   Of the 3 subatomic particles, the electron
    plays the greatest role in determining the
    physical and chemical properties of an
    element.
   There is a relationship between the electron
    configuration of elements and their
    arrangement in the table.

				
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