Atomic Orbitals

Where do we put all of the electrons?

Different Models of Same Atom

Reality Check• Lewis structures don’t represent what is going

on inside atoms with 100% accuracy. • But Lewis structures are useful tools that can

help us figure out chemical structures maybe 95% of the time.

• To understand what is really going on with the electrons inside of atoms we need to delve into quantum mechanics.

Quantum Mechanics• quantum – a small but incremental amount of

energy.• mechanics – study of motion and the causes

of motion.

• Weird Stuff – Quantum Leaps, You can’t pay me in pennies, Certain Uncertainty, Zombie cats, We are all made of Waves

Potential (aka Positional) Energy

It takes a certain amount of energy to move away from something that is pulling you.

• Potential Energy – the energy related to something’s position.

• Potential Energy – the energy related to something’s position.

• Objects have greater potential energy when they are further away from the Earth.

What about Potential Energy in Atoms?

• Potential Energy – the energy related to something’s position.

• Objects have greater potential energy when they are further away from the Earth.

• Electrons have greater potential energy when they are further away from the nucleus.

Quantum Leapabsorbed energy from light allows an electron to jump to a higher energy level

quantum – a distinct energy amount (no more, no less).

light

Quantum Dropreleased energy from light allows an electron to fall to a lower energy level

light

Quantum Dropreleased energy from light allows an electron to fall to a lower energy level

light

Einstein’s Photoelectric Effectphoto – having to do with light.electric – having to do with electrons.

The Photoelectric Effect

The Photoelectric Effect

Einstein’s Photoelectric Effect• Even though more red light hits the metal,

only the higher energy blue light causes the electrons to be leave the metal.

Einstein’s Photoelectric Effectphoton – a single particle (or packet) of light

Einstein’s Photoelectric Effectphoton – a single particle (or packet) of light

Orbitals• 2 electrons per orbital.

• Different shapes and energy levels.

s-orbitals

p-orbitals

px-orbital

x-axis

y-axis

z-ax

is

py-orbital

x-axis

y-axisz-

axis

pz-orbital

x-axis

y-axisz-

axis

d-orbitals

f-orbitals

So how many electrons can they hold?

Orbital Type

# of orbitals per energy

level

Full # of electrons

abbrev.

s-orbitals 1 2 e- s2

p-orbitals 3 6 e- p6

d-orbitals 5 10 e- d10

f-orbitals 7 14 e- f14

Where do they put all of these electrons?!

Where do they put all of these electrons?!

Where do they put all of these electrons!

Where do they put all of these electrons?!

Where do they put all of these electrons?!

Where they put all of these electrons?!

s-block

p-block

d-block

f-block

1 s orbital = 2 electrons

2e–

2e– 2e– 2e–

2e– 2e– 2e– 2e– 2e–

2e– 2e– 2e– 2e– 2e– 2e– 2e–

3 p orbitals = 6 electrons

5 d orbitals = 10 electrons

7 f orbitals = 14 electrons

7s 7p 7d 7f6s 6p 6d 6f5s 5p 5d 5f4s 4p 4d 4f3s 3p 3d2s 2p1s

Incr

easi

ng E

nerg

y

7s 7p 7d 7f6s 6p 6d 6f5s 5p 5d 5f4s 4p 4d 4f3s 3p 3d2s 2p1s

Incr

easi

ng E

nerg

y

?

8s 8p 8d 8f 7g 6g

5g ?

?

Incr

easi

ng E

nerg

y

1s

2s

3s

4s

5s

6s

7s

2p

3p

4p

5p

6p

3d

4d

5d

5f

4f

n = 1

n = 2

n = 3

n = 4

n = 5

n = 6

n = 7

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s1

H

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s2

He

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s1

Li

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s2

Be

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p1

B

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p2

C

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p3

N

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p4

O

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p5

F

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p6

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p63s1

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p63s2

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p63s23p1

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p63s23p2

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p63s23p3

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p63s23p4

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p63s23p5

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p63s23p6

Electron Configuration RulesPauli exclusion principle – no more than 2

electrons per orbital (no 2 electrons in an atom have same 4 quantum numbers).

Hund’s rule – electrons fill all of the suborbitals one at a time before they double up (favors having the same spin).

aufbau principle – electrons fill the orbitals with the lowest energy first.

2p

4 Quantum Numbers

(n, l, ml , ms )

Energy level (1, 2, 3, …)

Orbital shape or sublevel (s, p, d, f)

Orbital direction (px , py , pz)

Spin(+ ½, - ½)

Hybrid orbitals

• Example: tangerine + pomelo =

Sometimes atoms transform their own electron orbitals into hybrid orbitals so they can covalently bond with other atoms.

• hybrid – a mixture of 2 different types of something.

• Example: donkey + horse = • Example: gasoline

engine + electric motor =

tangelomule

hybrid car

s and p orbital hybridization1 s + 1 p = 2 sp orbitals

1 s + 2 p = 3 sp2 orbitals

1 s + 3 p = 4 sp3 orbitals

Weekend Homework Contest• In your home, find the most bizarre ionic

compound that you can:

• Write down: 1) where it was found (food, cleaning supply, etc.)

2) ingredient name on the label3) ionic formula (or what you

think it is)

• Example: 1) Chlorox Bleach2) sodium hypochlorite3) NaClO

NeFONCBBe

He

Li

H

Kr

ArCl

Br

XeI

SPSiMg Al

Ca

Na

K

NeFONCBBe

He

Li

H

Kr

ArCl

Br

XeI

SPSiMg Al

Ca

Na

K

Incr

easi

ng E

nerg

y

1s

2s

3s

2p

3p

n = 1

n = 2

n = 3

electron configuration:

1s22s22p63s23p6

4 e– in valence shell

So how many electrons can they hold?

Orbital Full # of type electrons abbrev.s-orbital 2 electrons s2

p-orbitals 6 electrons p6

d-orbitals 10 electrons d10

f-orbitals 14 electrons f14

C CH H