Download presentation

Published byTurner Limbrick Modified over 2 years ago

1
**3-Atomic Structure Overview Characteristics of Atoms**

Interaction b/tw matter and light Photoelectric Effect Absorption and Emission Spectra Electron behavior Quantum numbers

2
**Atomic Structure Atomic orbitals Periodic table Orbital energies**

Electron configuration and the periodic table Periodic table Periodic properties Energy

3
**Characteristics of Atoms**

Atoms possess mass Atoms contain positive nuclei Atoms contain electrons Atoms occupy volume Atoms have various properties Atoms attract one another Atoms can combine with one another to form molecules

4
Atomic Structure Atomic structure studied through atomic interaction with light Light: electromagnetic radiation carries energy through space moves at 3.00 x 108 m/s in vacuum wavelike characteristics

5
**Electromagnetic Spectrum**

6
Visible Spectrum

7
**Wavelength () & Frequency ()**

amplitude = number of complete cycles to pass given point in 1 second

8
**Energy c = x = 3.00 x 108 m/s long wavelength low frequency**

Low Energy High Energy short wavelength high frequency

9
**Energy Mathematical relationship: E = h E = energy**

h = Planck’s constant: 6.63 x 10–34 J s = frequency in s–1

10
**Energy Mathematical relationship: E = h c = x E =**

Energy: directly proportional to frequency inversely proportional to wavelength

11
Problems 3-1, 2, & 3 a) Calculate the wavelength of light with a frequency = 5.77 x 1014 s–1 b) What is the energy of this light? 2. Which is higher in energy, light of wave-length of 250 nm or light of 5.4 x 10–7 m? 3. a) What is the frequency of light with an energy of 3.4 x 10–19 J? b) What is the wavelength of light with an energy of 1.4 x 10–20 J?

12
**Photoelectric Effect Light on metal surface Electrons emitted**

Threshold frequency, o If < o, no photoelectric effect If > o, photoelectric effect As , kinetic energy of electrons

13
**Photoelectric Effect Einstein: energy frequency**

If < o electron doesn’t have enough energy to leave the atom If > o electron does have enough energy to leave the atom Energy is transferred from light to electron, extra is kinetic energy of electron Ephoton = hphoton = ho + KEelectron KEelectron = hphoton – ho Animation

14
Problem 3-4 A given metal has a photoelectric threshold frequency of o = 1.3 x 1014 s1. If light of = 455 nm is used to produce the photoelectric effect, determine the kinetic energy of the electrons that are produced.

15
**Bohr Model Line spectra Light through a prism continuous spectrum:**

Ordinary white light

16
**Bohr Model Line spectra Light from gas-discharge tube**

through a prism line spectrum: H2 discharge tube

17
**Line Spectra (emission)**

White light H He Ne

18
**Line Spectra (absorption)**

Gas-filled tube Light source

19
**Bohr Model For hydrogen: C = 3.29 x 1015 s–1**

Niels Bohr: Electron energy in the atom is quantized. n = 1, 2, 3,…. RH = 2.18 x 10–18 J

20
**Bohr Model E = Ef – Ei = h Eatom = Eelectron = h Line spectrum**

Minus sign: free electron has zero energy Line spectrum Photoelectric effect:

21
Bohr Energy Levels

22
**Electrons All electrons have same charge and mass**

Electrons have properties of waves and particles (De Broglie)

23
**Heisenberg Uncertainty Principle**

Cannot simultaneously know the position and momentum of electron x = h Recognition that classical mechanics don’t work at atomic level.

24
**Schrödinger Equation Erwin Schrödinger 1926**

Wave functions with discrete energies Less empirical, more theoretical n En n wave functions or orbitals n2 probability density functions

25
**Quantum Numbers Each orbital defined by 3 quantum numbers**

Quantum number: number that labels state of electron and specifies the value of a property

26
**Quantum Numbers Principal quantum number, n (shell)**

Specifies energy of electron (analogous to Bohr’s n) Average distance from nucleus n = 1, 2, 3, 4…..

27
**Quantum Numbers Azimuthal quantum number, (subshell) = 0, 1, 2… n–1**

n = 2, = 0 or 1 n = 3, = 0, 1, or 2 Etc. 1 2 3 4 s p d f g

28
**Quantum Numbers Magnetic quantum number, m**

Describes the orientation of orbital in space m = –….+ If = 2, m = –2, –1, 0, +1, +2

29
**Problem 3-5 Fill in the quantum numbers in the table below. n m 3**

3s 2 –2, –1, 0, 1, 2 2p

30
**Schrödinger Equation Wave equations: **

Each electron has & E associated w/ it Probability Density Functions: 2 -graphical depiction of high probability of finding electron

31
**Probability Density Functions**

Link to Ron Rinehart’s page energy 2 probability density function s, p, d, f, g 1s 3s 2s Node: area of 0 electron density

32
**Probability Density Functions**

Node: area of 0 electron density nodes Link to Ron Rinehart’s page

33
**Electrons and Orbitals**

Pauli Exclusion Principle: no two electrons in the same atom may have the same quantum numbers Electron spin quantum number ms = ½ Electrons are spin paired within a given orbital

34
**Electrons and Orbitals**

= 0, m = 0, ms = ½ 2 electrons possible: 1,0,0,+½ and 1,0,0,–½ 2 electrons per orbital 1s1 H 1s2 He

35
**Electrons and Orbitals**

= 0, m = 0, ms = ½ 2,0,0, ½ 2 electrons possible = 1, m = –1,0,+1, ms = ½ 2,1,–1, ½ ,1,0, ½ 2,1,+1, ½ 6 electrons possible

36
**Electron Configurations**

1s 2 electrons possible H 1e– 1s1 He 2e– 1s2

37
**Electron Configurations**

2s 2 electrons possible Li 3e– 1s2 2s1 2s 1s Be 4e– 1s2 2s2 2s 1s

38
**Electron Configurations**

2p = 1, m = –1, 0, +1 3 x 2p orbitals (px, py, pz): 6 electrons possible 2p B 5e– 1s2 2s2 2p1 2s 1s

39
**Electron Configurations**

2p = 1, m = –1, 0, +1 3 x 2p orbitals (px, py, pz): 6 electrons possible 2p B 5e– 1s2 2s2 2p1 2s 1s

40
**Electron Configurations**

2p = 1, m = –1, 0, +1 C 6e– 1s2 2s2 2p2 1s 2s 2p Hund’s Rule: for degenerate orbitals, the lowest energy is attained when electrons w/ same spin is maximized

41
Problem 3-6 Write electron configurations and depict the electrons for N, O, F, and Ne.

42
**Electron Configurations**

3s, 3p, 3d 1s 2s 2p 3s 3p Na 11e– 1s2 2s2 2p63s1

43
**Electron Configurations**

3s, 3p, 3d 1s 2s 2p 3s 3p Mg 12e– 1s2 2s2 2p63s2

44
**Electron Configurations**

3s, 3p, 3d 1s 2s 2p 3s 3p Al 13e– 1s2 2s2 2p63s23p1

45
**Electron Configurations**

3s, 3p, 3d 1s 2s 2p 3s 3p Si 14e– 1s2 2s2 2p63s23p2

46
**Electron Configurations**

3s, 3p, 3d 1s 2s 2p 3s 3p P 15e– 1s2 2s2 2p63s23p3

47
**Electron Configurations**

3s, 3p, 3d 1s 2s 2p 3s 3p S 16e– 1s2 2s2 2p63s23p4

48
**Electron Configurations**

3s, 3p, 3d 1s 2s 2p 3s 3p Cl 17e– 1s2 2s2 2p63s23p5

49
**Electron Configurations**

3s, 3p, 3d 1s 2s 2p 3s 3p Ar 18e– 1s2 2s2 2p63s23p6

50
**Electron Configurations**

3d vs. 4s Filling order 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 5g 6s 6p 6d 7s 7p

51
**Electron Configurations**

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

52
**Electron Configurations**

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

53
**Electron Configurations**

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

54
**Electron Configurations**

4p Ti 3d 4s 3p 3s 2p 2s Link to OSU site 1s

55
Problem 3-7 Write the electron configurations for the transition metals V – Zn. Fill in the corresponding boxes to denote the electronic spin.

Similar presentations

Presentation is loading. Please wait....

OK

1 The Quantum Mechanical Model of the Atom Chapter 7.

1 The Quantum Mechanical Model of the Atom Chapter 7.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on cell the basic unit of life Ppt on digital media marketing Ppt on formal non-formal and informal education 360 degree customer view ppt on mac Easy ppt on global warming Corporate brochure ppt on architectural firm Gastrointestinal system anatomy and physiology ppt on cells Ppt on organic farming vs chemical farming Ppt on minimum wages act mumbai Ppt on the rise of nationalism in europe