Unit #1Unit #2Unit #3Unit #4Unit #5Unit #6Unit #7Unit #8Unit #9Unit #10
spacerUNIT # 3  
spacerspacerIntroduction
spacerspacerObjectives
spacerspacerReading

spacer3.1
Structure
spacerof the Atom

spacerAtomic Number - Number of Protons
spacerNumber of Electrons
spacerMass Number - Number of Neutrons
spacer3.2 Isotopes
spacer3.3 Arrangement
spacerof Electrons

spacerThe Bohr Model
spacerBohr Diagram
spacerThe Lewis Electron-dot Symbol
spacerThe Quantum Mechanical Model of the Atom
spacerElectrons in the sublevels

spacer3.4 Electron
spacerConfigura
tions

spacerFilling Order of the Sublevels

spacerElectron Configuration Notations
spacerElectron Configuration for Atoms of the First 20 Elements
spacerElectron Configuration and the Periodic Table
spacer3.5 Atomic Mass
spacerCalculation of Atomic Mass
spacerCalculate the Atomic Mass of Carbon

spacerspacerProblems
spacer1 | 2 | 3
   

Unit #3 ATOMIC STRUCTURE

3.4 - Electron Configurations of Atoms

3.4.4 - Electron Configuration and the Periodic Table

There is a pattern between the electron configuration for the elements and their positions on the periodic table. You should take a look at section 3.6.3 and look closely at the first 20 elements. Compare the electron configuration of an element and its position on the periodic table.

  • Elements belonging in Group IA (eg - H, Li, Na, K) all have electron configuration ending in ns1
    (the superscript of '1' indicates there is 1 valence electron for elements belonging to Group IA).
  • Elements belonging in Group IIA (eg - Be, Mg, Ca) all have electron configuration ending in ns2
    (the superscript of '2' indicates there are 2 valence electrons for elements belonging to Group IIA).
  • Elements belonging in Group IIIA (eg - B, Al) all have electron configuration ending in ns2np1
    (the superscripts total to '3' indicates there are 3 valence electrons for elements belonging to Group IIIA).
  • Elements belonging in Group IVA (eg - C, Si) all have electron configuration ending in ns2np2
    (the superscripts total to '4' indicates there are 4 valence electrons for elements belonging to Group IVA).
  • Elements belonging in Group VA (eg - N, P) all have electron configuration ending in ns2np3
    (the superscripts total to '5' indicates there are 5 valence electrons for elements belonging to Group VA).
  • Elements belonging in Group VIA (eg - O, S) all have electron configuration ending in ns2np4
    (the superscripts total to '6' indicates there are 6 valence electrons for elements belonging to Group VIA).
  • Elements belonging in Group VIIA (eg - F, Cl) all have electron configuration ending in ns2np5
    (the superscripts total to '7' indicates there are 7 valence electrons for elements belonging to Group VIIA).
  • Elements belonging in Group VIIIA (eg - He, Ne, Ar) all have electron configuration ending in ns2np6
    (the superscripts total to '8' indicates there are 8 valence electrons for elements belonging to Group VIIIA).

Compare this to what you learned in section 3.3.2. Click to see the periodic table in terms of electron configurations.

 

Section 4.8
Arrangement of Electrons in Sublevels ..p96

Section 5.3
General Characteristics of the Groups ..p109


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