Transcript Slide 1

What we know (about atoms, specifically hydrogen):
•There is a nucleus
•Electrons (wave/particles) are around the nucleus
•The location of the electron is not absolutely
known…but the probable positions can be
calculated with the wave equation.
•These locations are called orbitals (the wave
function, Y)
•Orbitals can be pictured as boundary surface or
contour diagrams.
•The orbital depends upon the total energy of the
electron
•This can be determined by the set of quantum
numbers for the electron
Multi-Electronic Atoms
Total energy of the electron
Electrostatic interactions will
influence the potential
energy
The “electron
correlation problem”
Since electron
pathways are
unknown…electronelectron repulsions can
not be calculated
exactly
•nucleus-electron (attractions)
•electron-electron (repulsions)
Zeff = Zact – repulsive effects
2p+
e-
eHe the
atom
The
amount of
energy the
electron
must
receive to
be taken to
the infinite
energy
level
Ionization energy
= 3.94 x 10-21 kJ
Charge felt by the
electron from the nucleus
is apparently lessened!
2p+
produces
Potential energy electron possesses as a result of what it appears to
feel from the nucleus can be simulated in the Wave Equation to
calculate possible positions were electron can be found:
e-
Hydrogenlike orbitals
He the
ion
Ionization energy
= 8.718 x 10-21 kJ
Rules for configuring electrons in orbitals
•The AUFBAU Principle: Fill up the lowest
energy orbitals available first.
•The PAULI EXCLUSION Principle: No electron in
the same atom can have the same set of quantum
numbers (i.e. only two electrons per orbital).
•HUNDS Rule: Fill up degenerate orbitals
individually with the same spin before you pair
them up.
x
1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d 5f
6s 6p 6d 6f
7s 7p 7d 7f
Outermost Configuration &
Number of Unpaired Electrons
Outside Desks ….Hafnium
2
5d ,
2 unpaired electrons
Inside Desks ….Holmium
4f11, 3 unpaired electrons