What is an atom's electron configuration?
RECAP: Orbitals
Probability to find electron at a given orbital
Pauli's Exclusion Principle
2 electrons cannot have the same quantum numbers
Orbital Energy 
Energy required to remove each electron from it's appropriate orbital (also known as ionization energy).
Aufbau relationship to periodic table

Aufbau Principle - order in which E are filled

Orbital Diagram

How are electrons orbitals filled?

Ex. C is 1s22s22p2

Stable Electron Configurations
Stable 
  • Filled shell is very favorable.
  • (much weaker) Half-filled orbital - so one electron in each 
Bonding
Unstable 
Interaction between the outer (valence) electrons in order to lower their energy (completion of the shell) 
Valence electrons

Outermost electrons:

Cl: 1s22s22p63s23p5

Ionic
Covalent
Metallic
Electron Property
Electron exchange
Nondirectional 
Ex. NaCl, attracted to each other because Na becomes cation, Cl anion. Nondirectional because does not matter the angle which Na and Cl are at, only how close they are 
Electron Property
Electron sharing
Directional
Ex. ethane C2H6
Directional because each atom prefer to be at a specific direction
Electron Property
Electron sharing
Nondirectional
Sea of electrons.  Average electron density = # valence electrons! 
Ceramics
High melting points, brittle, etc
------------------------
| - + - + - + - + - + |
| + - + - + - + - + - |
------------------------
Electronegativity
Quantificaton of the element's desire for an electron (see pg 26 in book)
Electron screening: filled inner electron shells sort of block out the proton pull for the outer shelled electrons  
Properties
Conductivity, heat conduction bc of the sea of electrons. Malleability make sense too bc interaction is 
Shiny bc sea of electrons 
   Login to remove ads X
Feedback | How-To