Transcript QUANTUM MECHANICAL MODEL

QUANTUM MECHANICAL
MODEL
Determines the allowed
energies an electron can have
Determines how likely it is to
find the electron in various
locations
QUANTUM MECHANICAL
MODEL
 CLOUD or ORBITAL MODEL
 PROPABILITY OF FINDING AN
ELECTRON WITHIN A CERTAIN
VOLUME OF SPACE AROUND THE
NUCLEUS (orbital)
 High density =high propability
 Low density =low probability
 Shape of the cloud represents a 90%
probability
QUANTUM MECHANICAL
MODEL GENERAL PLAN
 PRINCIPLE ENERGY LEVEL (n)
 ENERGY SUBLEVELS (l)
indicate the shape of orbital
which contains
 ATOMIC ORBITALS (m)
Orientation of orbital around
nucleus
(Electrons found here)
 Number of electrons per atomic orbital
=2
QUANTUM MECHANICAL
MODEL
principle energy levels
 PRINCIPLE ENERGY LEVELS
 LABELED BY PRINCIPLE QUANTUM
NUMBERS (n) n=1,2,3,4,5,6,etc.
 As n> the electrons energy > and
distance from nucleus >
 Can be called a shell
 Within a given energy level there may
be several sublevels that have orbitals
QUANTUM MECHANICAL
MODEL
energy sublevels
 ENERGY SUBLEVEL (l)
 Each energy sublevel corresponds to
orbitals of different shapes where
the electron is likely to be found
 Sublevel could be called a subshell
QUANTUM MECHANICAL
MODEL
energy sublevels
 ENERGY SUBLEVEL (l)
(Orbital shapes)
 Labeled by letters
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s = spherical shape
p = dumbbell shape
d = clover leaf +
f = too complicated
QUANTUM MECHANICAL
MODEL
atomic orbitals
 ATOMIC ORBITAL (m)
(Orbital orientation)
 THE s SUBLEVEL HAS ONLY ONE
ORBITAL, s
QUANTUM MECHANICAL
MODEL
atomic orbitals
 Atomic orbital
(orbital
orientation)
 THE p SUBLEVEL HAS THREE
ORBITALS—px, py, pz
QUANTUM MECHANICAL
MODEL
atomic orbitals
 Atomic orbital (orbital
orientation)
 THE d SUBLEVEL HAS 5 ORBITALS–
dxy, dxz, dyz, dx2-y2,dz2
QUANTUM MECHANICAL
MODEL
atomic orbitals
 Atomic orbital(orbital
orientation)
 THE f SUBLEVEL HAS 7
ORBITALS
 They are too complicated to
show or name
QUANTUM MECHANICAL
MODEL
electron location
Within each orbital there
can be a maximum of 2
electrons
EACH ELECTRON MUST
HAVE AN OPPOSITE SPIN+1/2 or -1/2
QUANTUM MECHANICAL
MODEL
RELATIONSHIPS
 Relationships between
 Energy levels n=energy level
 SUBLEVELS n=number OF
SUBLEVELS
 ORBITALS n2=number OF ORBITALS
PER ENERGY LEVEL
 ELECTRONS 2n2= MAXIMUM
NUMBER OF ELECTRONS PER
ENERGY LEVEL
QUANTUM MECHANICAL
MODEL
SUMMARY
Organization
Principle energy level
(shell)
Sublevel (subshell)
Atomic orbital
Spin
Designation
Energy
Level
n=1
n=2
n=3
n=4
Subshells or
sublevel
# of Orbitals
Maximum
number of
e-s per
orbital
Total
number of
e-s per
energy level
QUANTUM MECHANICAL
MODEL
 Electron configuration
 The relationship between energy and
stability
 Electrons and nucleus interact to make
the most stable arrangment possible
(lowest energy)
 There are three rules for electron
configurations
QUANTUM MECHANICAL
MODEL
 Electron configuration
 Aufbau princple
 Electrons occupy the
orbitals of lowest energy
first
QUANTUM MECHANICAL
MODEL
 AUFBAU RULE
QUANTUM MECHANICAL
MODEL
 AUFBAU ORDER FILLING
QUANTUM MECHANICAL
MODEL
 Electron configuration
 Pauli exclusion principle
 One orbital may describe at most
2 electrons
 To occupy the same orbital, the
two electrons must have opposite
spins
↑↓
QUANTUM MECHANICAL
MODEL
 Electron configuration
 Hunds rule
 When filling orbitals of equal
energy, one electron occupies
each orbital until all orbitals
contain one electron with the
same spin direction
QUANTUM MECHANICAL
MODEL
 Electron arrangement
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Orbital notation
Electron configuration notation
Exceptions
Half-filled sublevels are less
stable than filled sublevels but
more stable than other
configurations