Inorganic Chemistry Notes Ch2

Only available on StudyMode
  • Topic: Electron configuration, Atom, Pauli exclusion principle
  • Pages : 3 (565 words )
  • Download(s) : 165
  • Published : September 13, 2012
Open Document
Text Preview
Chapter 2: Atomic Structure
Quantum Numbers
n: principal, energy, size of orbital, positive integers allowed
l: angular momentum, orbital shape, integers from 0 to n-1 allowed
ml: magnetic moment, orientation in space of orbital, integers from -l to +l allowed
ms: spin, shows electrons in orbital, ± ½ allowed
Orbitals
p orbital
l = 1
All have a specific orientation in space (x, y, z)

Electron spends equal amount of time in both lobes, nucleus at node
Shading shows positive and negative values of wavefunction (assymetrical with respect to inversion
d orbital
l = 2
d orbitals have 5 orientations in space
dyx, dxy, dxz, dz2
Symmetrical with respect to inversion
Filling out orbitals
Each orbital has a max of 2 electrons
Pauli exclusion principle: no 2 electrons in an atom can have the same 4 quantum numbers
Up spin filled first
Takes less energy
Each orbital has its up-spin filled first so as to minimize Coulombic repulsion
Hund’s Rules of Maximum of Multiplicity
Multiplicity = unpaired electrons + 1
Higher is better
Coulombic energy of repulsion (ΠC)
Two electrons in the same orbital have higher energy than two electrons in different orbitals
Coulombic energy of exchange (Πe)
Possible exchanges between two electrons with the same energy and spin (more available exchanges is better)
Repulsion energy is destabilizing (ΠC>0), exchange energy is stabilizing (Πe<0)
Π = ΠC + Πe
Electrons are placed in orbitals to give the lowest total energy to the atom
Orbitals filled using Aufbau
Chromium, Molybdenum, Copper, Silver, and Gold are all exceptions to the Aufbau principle
Cr: [Ar] 4s1 3d5
Many times, half-filled and completely filled orbitals are unusually stable, so sigma electrons can rarely end up promoted to pi electrons
Types of electrons
Valence: outer electrons responsible for chemistry
Transition metals: Any...
tracking img