• Erwin Schrodinger proved

Bohr’s idea wrong

• Said electrons do not move

around in fixed orbits around

the nucleus

• But rather proved that

electrons move in 3D areas

around the nucleus

• Showed the probability of

where an e- may be in the

atom

Today’s

Atom

Energy

Levels,

Sublevels

and

Orbitals

• Within the energy levels

are 3D areas called

sublevels that have their

own significant shape

• Inside sublevels there are

orbitals, where e- are

arranged

Sublevel

name

# of

orbitals# of e-

s 1 2

p 3 6

d 5 10

f 7 14

• s is the first and

simplest sublevelShape of

“s”

sublevel

• p is the second sublevelShape of

“p”

sublevel

Shape of “d” sublevel

Shape of “f” sublevel

All electrons follow three rules when filling energy levels and sublevels. They are:

• Aufbau Principle

• Pauli Exclusion Principle

• Hund’s Rule

1s2s2p3s3p

Orbital

Diagrams

• An e- occupies the

lowest energy orbital

that can receive it.

• Start at the bottom

Aufbau

Principle

The Hotel Californium

1st floor

2nd floor

5th floor

n = 1

n =2

n = 5

= electron

Aufbau

Principle

• A maximum of two

electrons may occupy a

single orbital, but only

if the electrons have

opposite spins

• Two e- per orbital, one

up, one down

Pauli

Exclusion

Principle

• Orbitals of equal energy

are each occupied by

one e- before any orbital

is occupied by a second

e- and all e-s in singly

occupied orbitals must

have the same spin

state.

• Split them up before you

pair them up

Hund’s

Rule

Hund’s

Rule

• Includes a line for each

of the atom’s orbitals

• Lines are filled with

arrows representing

electrons

▪ Up and down facing

arrows to show opposite

spins

Orbital

Diagrams

Sublevel

name

# of

orbitals

Amt. of

Electrons

s 1 2

p 3 6

d 5 10

f 7 14

sublevel # of lines # of arrows in

sublevel

Sublevels,

orbitals &

# of

electrons

Orbital Diagrams

1s

2s 2p

3s 3p 3d

4s 4p 4d 4f

5s 5p 5d 5f

6s 6p 6d 6f

7s 7p 7d 7f

1s2s2p3s3p4s3d

Incr

easi

ng e

ner

gy

Start on bottom of first arrow,

go up the arrow, then go to

bottom of the next arrow, go up

the arrow and repeat

• Remember the rules

electrons follow when

filling energy levels,

sublevels and orbitals

▪ Aufbau Principle

▪ Pauli Exclusion Principle

▪ Hund’s Rule

• Let’s determine the

orbital diagram for

Phosphorus

▪ 15 electrons

Orbital

Diagrams

1s

2s 2p

3s 3p 3d

4s 4p 4d 4f

5s 5p 5d 5f

6s 6p 6d 6f

7s 7p 7d 7f

7p

6d

5f

7s

6p

5d

4f

6s

5p

4d

5s

4p

3d

4s

3p

3s

2p

2s

1s

Orbital diagram

for 118 electrons

Filling in Orbital Diagrams:

• The first 2 e- go into 1s orbital

(line )

• only 13 more to go...

• Next e- go into 2s orbital

• only 11 more…

• Next e- go into 2p orbital

• Up, up, up then down, down, down

• only 5 more…

• Next e- go into 3s orbital

• only 3 more…

• Last e- go into 3p orbital

• e- by themselves before being

paired

• 3 unpaired e-

1s2s2p3s3p4s3d

Notice the opposite

spins (one ↑, one ↓)

• Determine the orbital

diagram for the

following:

▪ Cobalt (Co)

▪ Germanium (Ge)

1s2s2p3s3p4s3d

Cobalt – 27 e- Germanium – 32 e-

1s2s2p3s3p4s3d

4p

7p

6d

5f

7s

6p

5d

4f

6s

5p

4d

5s

4p

3d

4s

3p

3s

2p

2s

1s