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)