Themes of the Day:

• Exam #1 Review
• Electron Configuration and the Organization of the Periodic Table
• Ions & Chemical Bonding

Exam #1 Review

• Exam #1 Study Guide

Electron Configuration and the Organization of the Periodic Table

• Quantum Numbers
  • Principal: n
    positive integers: 1, 2, 3, ...
    2n² = maximum # of electrons in shell
    

    n	1	2	3	4	...
    Shell	K	L	M	N	...

  • Angular Momentum: l
    0 to n-1
    2p refers to n = 2, l = 1

    l	0	1	2	3	...
    Subshell	s	p	d	f	...

    
    note: d orbitals have a big impact on color
  • Magnetic: m_l
    +l to -l
    Orbital Geometry of the s, p, and d subshells
  • Spin: m_s
    +1/2 or -1/2
• Orbital Energy
• Common Charges [note: errors for Ti, V]
  for a better representation see An Earth Scientist's Periodic Table of the Elements and Their Ions and its explanation
• Traditional Periodic Table showing electron configurations
• Web Elements

Ions

• Ions - charged atoms with # of electrons not equal to # of protons - important for bonding
  • Anions - negative charge - # of Electrons > # of Protons - ex. Chlorine (Cl^-), Oxygen (O^2-)
  • Cations - positive charge - # of Electrons < # of Protons - ex. Sodium (Na⁺), Magnesium (Mg²⁺)
• Ionic charge = valence = oxidation state
• Periodic Table - helps predict ionic charges
• Electronegativity - Linus Pauling (1960) - propensity to gain or lose electrons - the difference in electronegativity between cation and anion can be related to the percent ionic character of the bond (more below)
• Ions with similar charges and sizes may substitute for each other in some minerals
• Abundance of elements in the Earth's crust:

  Element	Chemical Symbol and Common Ion(s)	Percent (by weight)
  Oxygen	O2-	46
  Silicon	Si4+	28
  Aluminum	Al3+	8
  Iron	Fe2+ or Fe3+	6
  Magnesium	Mg2+	4
  Calcium	Ca2+	2.4
  Potassium	K1+	2.3
  Sodium	Na1+	2.1
  All others		<1