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Atomic StructureSchrödinger equation has approximate solutions for multi-
electron atoms, which indicate that all atoms are like hydrogen
Atomic StructureSchrödinger equation has approximate solutions for multi-
electron atoms, which indicate that all atoms are like hydrogen
1s
2s 2p
3s 3p 3d
Energy
1s
2s 2p
3s 3p 3d
Energy
hydrogen multi-electron
Atomic Structure
• orbitals are populated by electrons according to certain rules
Additional quantum number!
! spin quantum number (ms)
spin -1/2 spin +1/2
Atomic Structure
• orbitals are populated by electrons according to certain rules
Name Symbol Permitted Values Property
Principal n 1, 2, 3, etc orbital size (energy)
Angular Momentum l 0 to n-1 orbital shape
Magnetic ml-l to 0 to +l orbital orientation
Spin ms+1/2 or –1/2 direction of e- spin
Atomic Structure
• orbitals are populated by electrons according to certain rules
exclusion principle: no two electrons in the same atom
can have the same four quantum numbers
Atomic Structureexclusion principle: no two electrons in the same atom
can have the same four quantum numbers
an orbital
electrons
Atomic Structureexclusion principle: no two electrons in the same atom
can have the same four quantum numbers
an orbital
electrons
empty
Atomic Structureexclusion principle: no two electrons in the same atom
can have the same four quantum numbers
an orbital
electrons
empty
one electron
Atomic Structureexclusion principle: no two electrons in the same atom
can have the same four quantum numbers
an orbital
electrons
empty
one electron
two electron
only three options!
Atomic Structure
• orbitals are populated by electrons according to certain rules
exclusion principle: no two electrons in the same atom
can have the same four quantum numbers
Electron Shielding Effects:
different levels
higher Eionizationlower Eionization
n = 4 n = 1
Electron Shielding Effects
inner shells
higher Eionizationlower Eionization
n = 2
Electron Shielding Effects:
same orbital
higher Eionizationlower Eionization
2+ 2+
2+ 2+
He
He+
He+
He2+
Energy Profile of Sublevels
> f > d > p > s
l = 3 l = 2 l = 1 l = 0
Energy Profile of Sublevels
1s
E
N
E
R
G
Y
Energy Profile of Sublevels
1s
2s
2p
E
N
E
R
G
Y
Hund’s rule: maximum
number of unpaired electronsfor the same sublevel (n, l)
Energy Profile of Sublevels
1s
2s
2p
3s3p
E
N
E
R
G
Y
Energy Profile of Sublevels
1s
2s
2p
3s3p
3d4s
4pE
N
E
R
G
Y
Types of Electrons
! inner (core) electrons: those in the previous
noble gas
! outer electrons: after that highest energy levels
! valence electrons: same as outer, involved in
forming chemical bonds
Practice Problems
8.44. One reason spectroscopists study excited states is to
gain information about the energies of orbitals that are
unoccupied in an atom’s ground state. Each of the
following electron configurations represent an atom in an
excited state. Identify the element and write its condensed
ground-state configuration.
(a) 1s22s22p63s1
(b) 1s22s22p63s23p64s23d44p1
(c) 1s22s22p63s23p44s1
(d) 1s22s22p53s1
Trends in Periodic Table
metallic behavior increases
ionization energy decreases
Trends in Periodic Table
Non-metallic behavior increases
electron affinity increases
Practice Problems
8.68. Which element would you expect to be more metallic?
(a) Ca or Rb
(b) Mg or Ra
(c) Br or I
(d) Si or P
I or Se?
Practice Problems
Sample 8.6. Using condensed electron configurations,
write reactions for the formation of the following
elements:
(a) Iodine (Z=53)
(b) Potassium (Z=19)
(c) Indium (Z=49)