waves amplitude

wavelengthfrequency

light

energy level

cres

t

origin

ROYGBIV

electrons

EMS

energy

Photoelectric effect

http://youtu.be/xiMApWz5wsI

Electron.1

Wave nature of light› Electromagnetic (EM) radiation- E emits wave

like behavior › All waves have:

Wavelength- () distance from crest to crest Frequency- () # waves past a given point per

second (s-1) Amplitude- height of wave from crest to origin

› All light travels at speed of light, c = 3.00 x 108 m/s                    c=

Electron -1

EM spectrum› Radio  Microwave  Infrared Visible  UV  X-

ray Gamma Low E          High E

High            Low Low           High  

› Visible Light: Continuous spectrum ROYGBIV Low E     High E

High      Low Low       High

Electromagnetic Spectrum

ROYGBIV

Violet: 400- 420 nm Blue: 420- 490 nm Green: 490- 580 nm Yellow: 580- 590 nm Orange: 590- 650 nm Red: 650-700 nm

Electron -1

What is the frequency of green light, which has a wavelength of 4.90 x 10-7 m?

An X-ray has a wavelength of 1.15 x 10-10 m. What is its frequency?

A popular radio station broadcasts with a frequency of

9.47 x 107 s-1. What is the wavelength of the broadcast?

Hz = waves/sc= 3.00 x 108 m/s

Electron -1

Particle Nature of light › Quantum- minimum amount of E gained or

lost by an atom › Quantitized E- E gained in packet (NOT

continuous) E=hn 

E= energy in Jh= Planck’s Constant 6.6262 x 10-34Js= frequency (s-1) 

Electron -1

What is the energy of each of the following types of radiation?› 6.32 x 1020 s-1

› 9.50 x 1013 Hz› 1.05 x 1016 s-1

What types of radiation are the above?

Electron -1

Photoelectric effect- › Photoelectrons are emitted from a metals

surface when light of certain frequency shines on it Ex. solar calculators, automatic doors

› Each metal has its threshold for the photoelectric effect

› If light is shined on metal that doesn’t have the correct frequency, no matter how long, e- will not be emitted  

Lab Conclusion Due tomorrow! Must be typed. Explain what you did in the lab. Explain what happened. Explain the science behind what

happened (photoelectric effect). How you calculated wavelength,

frequency, and energy & identified the unknown salts.

Reflection…what you liked, what you didn’t like (if any).

Electron -1

Atomic Emission Spectra › e- excited will jump to another E level,› As they fall they emit E (light) › n of the waves allow for a unique color

(NOT a continuous color spectrum like a white light)

› Atomic Emission

Electron -2 Bohr- e- only have “allowable E states”

› Normally in ground state› e- around nucleus in orbits› Lower the E, closer the orbit to the nucleus› Quantum number (n)- lowest E state

• DeBroglie- all moving particles have

wave-like characteristics

Electron -2 Heisenburg Uncertainty Principle

› Can’t know velocity & position of e- at same time 

Schrodinger-quantum mechanical model of atom using wave properties of e- predicts e- will be found in orbitals, increase D of cloud = higher probability of e-  

Electron -2 Principle quantum number (n)- tell

relative sizes & shapes of orbitals Higher n = bigger orbital = increased

time of e- away from nucleus Levels contain same number of

sublevels as level numberLevel Sublevels Sublevel

Called

1 1 s

2 2 s, p

3 3 s, p, d

4 4 s, p, d, f

Electron -2

** Each orbital can only hold 2 e-

Sublevel # Orbitals # e- held

s 1 2

p 3 6

d 5 10

f 7 14

Electron -3

Aufbau principle- each e- occupies lowest E orbital available

Electron Configuration- arrangement of e- in orbitals around atom› Lower E more stable than high E› Lowest E= ground state

Example:

1s2 1 is n s is sublevel 2 is number of e- in sublevel & is a superscript 

› All orbitals in each E sublevel are equal (the three orbitals are =E) Fill s, p, d, f, for each level Orbitals can overlap

Electron Sequence Model

1s

2s

3s

4s

5s

6s

7p

6p

5p

4p

3p

2p

6d

5d

4d

3d

4f

5f

7s

Follow the yellow brick road

Electron Sequence by the Periodic Table

1s

La

Ac

1s

5f

4f

2s

3s

4s

5s

6s

7s

2p

3p

4p

5p

6p

3d

4d

5d

6d

The Periodic Table1

H3

Li11

Na19

K37

Rb55

Cs87

Fr

4

Be12

Mg20

Ca38

Sr56

Ba88

Ra

21

Sc39

Y57

La89

Ac

22

Ti40

Zr72

Hf104

Rf

23

V41

Nb73

Ta105

Db

42

Mo74

W106

Sg

25

Mn43

Tc75

Re107

Bh

26

Fe44

Ru76

Os108

Hs

27

Co45

Rh77

Ir109

Mt

28

Ni46

Pd78

Pt110

Uun111

Uuu

30

Zn48

Cd80

Hg

8

O16

S34

Se52

Te84

Po

7

N15

P33

As51

Sb83

Bi

6

C14

Si32

Ge50

Sn82

Pb

5

B13

Al31

Ga49

In81

Tl

9

F17

Cl35

Br53

I85

At

2

He10

Ne18

Ar36

Kr54

Xe86

Rn

90

Th91

Pa92

U93

Np94

Pu95

Am96

Cm97

Bk98

Cf99

Es100

Fm101

Md102

No103

Lr

58

Ce59

Pr60

Nd61

Pm62

Sm63

Eu64

Gd65

Tb66

Dy67

Ho68

Er69

Tm70

Yb71

Lu

24

Cr29

Cu47

Ag79

Au112

Uub114

Uuq116

Uuh118

Uuo

s

d

p

f

s1 s2 d1 d2 d3 d4 d5 d6 d7 d8 d9 d10 p1 p2 p3 p4 p5 p6

f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 f14

1

2

3

4

5

6

7

4

5

Electron -3

Electron Orbital Diagram: visually shows e- placement around the nucleus› Each orbital gets own box

Orbital # Orbitals # electrons held # boxes

s 1 2 1

p 3 6 3

d 5 10 5

f 7 14 7

Electron -3

Pauli Exclusion Principle- only 2 e- can occupy an orbital.  Each w/ opposite spins show w/ arrow up and down

NOT  Hund’s Rule- e- w/ same spin must occupy

each E level in a sublevel before doubling up› Example: when filling the p sublevel with 4e-, each

box gets 1 before doubling up one box

NOT 

Electron Configurations

F – 1s22s22p5

Cl – 1s22s22p63s23p5

Al – 1s22s22p63s23p1

Br - 1s22s22p63s23p64s23d104p5

1s 2s 2p 3s 3p 4s 3d 4p

1s 2s 2p 3s 3p 4s 3d 4p

1s 2s 2p 3s 3p 4s 3d 4p

1s 2s 2p 3s 3p 4s 3d 4p

Electron Configurations Sc

K

P

B

1s 2s 2p 3s 3p 4s 3d 4p

1s 2s 2p 3s 3p 4s 3d 4p

1s 2s 2p 3s 3p 4s 3d 4p

1s 2s 2p 3s 3p 4s 3d 4p

Electron -3

Other helpful hints- › #e= # p = atomic number if neutral atom› Add superscripts to get the #e, #p

Electron -3 Noble Gas Configuration

› Go back to the last noble gas› Write symbol for noble gas in brackets› Write rest of configuration

Na Complete Configuration: 1s22s22p63s1 

Na Noble gas Configuration: [Ne] 3s1  

Exceptions to electron configuration:› e- want to be stable› Stable is a full or ½ full e- shell› Cr- [Ar] 4s23d4 [Ar] 4s13d5

› Cu- [Ar] 4s23d9 [Ar] 4s13d10

Electron -3

Valence electrons- e- in outer most level› Put in noble gas configuration› Count e- in highest level

Ex: Na 1s22s22p63s1  has 1 valence e-

Cs [Xe] 6s1 has 1 valence e-

Cu [Ar] 4s13d10 has 1 valence e-

S [Ne] 3s23p4  has 6 valence e-

Lewis Dot Structures- shows valence e- around symbol 

Li    N  Be   O 

B    F  C    Ne

Properties of the d and f-Block Elements

Magnetism – ability to be affected by magnet

Diamagnetism – all e- are paired, substance is unaffected or slightly repelled by magnetic field

Paramagnetic – unpaired electron in the valence orbital is attracted to magnetic field

Ferromagnetism – strong attraction of substance, ions can align in direction of field and form permanent magnet