Historical Background of Quantum Mechanics

Size: px
Start display at page:

Download "Historical Background of Quantum Mechanics"

Transcription

1 Historical Background of Quantum Mechanics The Nature of Light The Structure of Matter Dr. Sabry El-Taher 1

2 The Nature of Light Dr. Sabry El-Taher 2

3 In 1801 Thomas Young: gave experimental evidence for the wave nature of light by showing that light exhibited refraction, diffraction and interference when passed through two adjacent pinholes. The diffraction pattern caused by light passing through two adjacent slits. Dr. Sabry El-Taher 3

4 Interference of Light Shine light through a crystal and look at pattern of scattering. Diffraction can only be explained by treating light as a wave instead of a particle. Dr. Sabry El-Taher 4

5 In 1865 Maxwell s Predictions: Maxwell provided a mathematical theory showed a relationship between all electric and magnetic phenomena. He unified the laws of electricity and magnetism in four equations. The equations predicted that an accelerated electric charge would radiate energy in the form of electromagnetic waves with speed equal to the speed of light (3x10 8 m/s). He concluded that visible light and all other electromagnetic (EM) waves consist of fluctuating electric and magnetic fields, with each varying field inducing the other. Dr. Sabry El-Taher 5

6 In 1888 Hertz: Hertz generated and detected electromagnetic waves experimentally. Hertz confirmed Maxwell s theory by showing that the waves detected had all the properties of light waves. Hertz measured the speed of the waves. It was very close to the speed of light. This provided first evidence in support of Maxwell s theory and convinced physicists that light is an electromagnetic wave. Dr. Sabry El-Taher 6

7 Electromagnetic Radiation Collection of energy waves with different wavelengths Emitted by all objects with temperature > 0 Kelvin EM radiation Properties: Wavelength (λ) = distance between two peaks (crest or trough) Frequency (ν) = number of cycles (waves) per second Speed (c) = x10 8 m/s ν λ = c Dr. Sabry El-Taher 7

8 Electromagnetic Spectrum Gamma Rays = shortest wavelength, highest energy (hazardous to health) UV radiation = can damage living tissue Visible radiation = region of EMS where our eyes are adapted to see µm Thermal radiation = heat given off by bodies Radio and TV waves = long, low energy waves (cm to m wavelengths) Dr. Sabry El-Taher 8

9 Electromagnetic Spectrum Dr. Sabry El-Taher 9

10 The Blackbody Radiation Perfect absorber of radiation. Theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. Perfect emitter of radiation. At a particular temperature the black body emits the maximum amount of energy possible for that temperature It was found that radiation emitted or absorbed by black-body changes with temperature Not all frequencies are emitted or absorbed with the same energy density. Dr. Sabry El-Taher 10

11 Stefan s law The total power of the emitted radiation increases with temperature P = σaet 4 Wien s displacement law As temperature is raised, the peak of the wavelength distribution,λ max moves toward shorter wavelengths (from red to blue) called blue shift Rayleigh Jeans Law Rayleigh and Jeans proposed that black-body consists of oscillators which can emit or absorb light at any frequency. Using classical physics and equipartition principle, they arrived at Rayleigh-Jeans Law: Dr. Sabry El-Taher 11

12 Rayleigh-Jeans law suggested that there can be emission of very short wavelength even at room temperature. In other word, there should be no darkness. (objects should glow in the dark.) It works quite well at low frequencies but does not predict the experimental data at higher frequencies. This Failure is called UV-catastrophe Planck took Rayleigh-Jeans s idea but instead of allowing oscillators to be able to emit or absorb light at any frequency each oscillator possesses only discrete values of energy. Dr. Sabry El-Taher 12

13 Planck s Quantum Hypothesis In 1900: Planck assumed that the radiation emitted was due to oscillations of the electrons in the constituent atoms of the body. Planck hypothesized that the energies of the electronic oscillators had to be proportional to an integer multiple of the frequency: He used Boltzman s statistical methods to arrive at the following formula that fit the blackbody radiation data. Dr. Sabry El-Taher 13

14 Planck was able to show that this equation gives excellent agreement with the experimental data for all frequencies and temperatures if h = x J.s Planck s distribution law is a macroscopic law, deduced from a microscopic hypothesis. Planck s hypothesis that only certain quantities of light energy could be emitted was in direct contradiction to classical physics. The quantization of energy principle states that energy is not absorbed or emitted continuously but rather in discrete units, each has energy of hν. He proposed that energy could only be emitted in discrete amounts, called quanta, each has energy equal to hν. This would be a complete break from classical physics, where all physical quantities are always continuous. Dr. Sabry El-Taher 14

15 The Photo-electric Effect In 1887: Hertz observed that UV light caused electrons to be emitted from the surface of a metal. Photoelectric effect: Incident light shining on the metallic surfaces transfers energy to the electrons, allowing them to escape. According to Classical Physics: The kinetic energy of the photoelectrons should increase with the light intensity and not depend on the light frequency. Dr. Sabry El-Taher 15

16 Experimental Observations The kinetic energy of the photoelectrons is independent of the light intensity. When photoelectrons are produced, their number (not their kinetic energy) is proportional to the intensity of light. Electron kinetic energy The kinetic energy of the photoelectrons depends only on the frequency of the light. A threshold frequency, ν 0, characteristic of the metallic surface, below which no photoelectrons are ejected. Dr. Sabry El-Taher 16

17 Einstein s Theory: Photons In 1905: Albert Einstein successfully explained the photoelectric effect by using Planck s quantum hypothesis. He suggested that the electromagnetic radiation field is quantized into particles called photons. Each photon has the energy quantum: Each photon is responsible for the emission of only one electron. When an electron absorbs a photon, part of the energy is used to escape the metal and the remainder appears as kinetic energy. Dr. Sabry El-Taher 17

18 An increase in the light s frequency increases the photon energy and hence increases the kinetic energy of the emitted electron. An increase in the light s intensity at fixed frequency increases the rate of emission of electrons, but does not change the kinetic energy of each emitted electron. The minimum frequency that will eject an electron is the frequency required to overcome the work function of the metal, hence The photoelectric effect shows that light can exhibit particlelike behavior in addition to the wave-like behavior. Dr. Sabry El-Taher 18

19 The Structure of Matter Dr. Sabry El-Taher 19

20 Thomson s Experiment (1897) J.J. Thompson He demonstrated that the cathode rays consist of negatively charged particles (called electrons). He was able to measure the charge-to-mass ratio of the electron: e/m = x 10 8 coulomb/gram The cathode rays that have the same e/m value are independent of the cathode metal or the type of gas, i.e., the cathode rays (electrons) are existed in all materials. Dr. Sabry El-Taher 20

21 Determination of Electron Charge Millikan was able to show that electrons had a particular charge. Millikan used X-rays to liberate electrons from the available gaseous atoms to charge the oil droplets. He used an electric field to balance gravity and suspend a charged oil drop. He was able to determine the charge of the oil drop by knowing its mass and the charge required to suspend it. He found that the charge of the droplet is a multiple of a quantized charge equal to -1.6 x C. He concluded that this value must be the electron charge. Robert A. Millikan ( ) Dr. Sabry El-Taher 21

22 Discovery of The Neutron In 1930 the known elementary particles were the proton, the electron, and the photon. Thomson identified the electron in 1897, and Einstein defined the photon in The proton is the nucleus of the hydrogen atom. Despite the rapid progress of physics in the first couple of decades of the twentieth century, no more elementary particles were discovered until 1932, when Chadwick proved the existence of the neutron. James Chadwick ( ) Dr. Sabry El-Taher 22

23 Questions left unanswered: 1. How are the electrons arranged around the nucleus? 2. what are their travel paths like? Dr. Sabry El-Taher 23

24 Dalton s Atomic Model (1807) The Billiard ball model. Atoms were considered to be featureless, indivisible, spheres of uniform density. Dr. Sabry El-Taher 24

25 Thomson s Atomic Model Thomson s plum-pudding model of the atom had the positive charges spread uniformly throughout a sphere, the size of the atom, with electrons embedded in the uniform background. Unfortunately, Thomson couldn t explain spectra with this model. Experimental results were not consistent with Thomson s atomic model. Dr. Sabry El-Taher 25

26 Alpha Scattering Experiment (1909): Rutherford s observations Most of the alpha particles passed through the foil. Alpha particles were shot into thin metal foil. A very few bounced back to the source! Ernest Rutherford ( ) A few particles were deflected slightly by the foil. Dr. Sabry El-Taher 26

27 Alpha Scattering Experiment: Rutherford s conclusions If Thomson s model of the atom was correct, most of the alpha particles should have been deflected a little. Most of the alpha particles passed through the foil => An atom must be mostly empty space. A very few alpha particles bounced back => The nucleus must be very small and massive. The nucleus is far smaller than is suggested here. Dr. Sabry El-Taher 27

28 Rutherford s Nuclear Model (1911) Rutherford proposed that: An atom has a central nucleus composed of positively charged protons. Negatively charged cloud of electrons surrounds the nucleus. Electrons orbit the nucleus like planets orbit the sun. The Planetary Model is Doomed From classical E&M theory, an accelerated electric charge radiates energy, the total energy must decrease. So the radius r must decrease!! Finally, Electron crashes into the nucleus! Dr. Sabry El-Taher 28

29 The Atomic Dimensions Dr. Sabry El-Taher 29

30 The Atomic Spectra 1. Continuous Spectrum 2. Emission Line Spectrum 3. Absorption Line Spectrum Dr. Sabry El-Taher 30

31 1. Continuous Spectrum A luminous solid or liquid, or sufficiently dense gas, emits light of all wavelengths (colors) and produces a continuous spectrum. Dr. Sabry El-Taher 31

32 2. Emission line spectrum A low-density, hot gas emits light whose spectrum consists of a series of discrete bright emission lines. These lines are characteristic of the chemical composition of the gas. Each line has a different wavelength and color. Dr. Sabry El-Taher 32

33 Examples of Emission Line Spectra The line emission spectrum of an element is a fingerprint for that element, and can be used to identify the element! Line spectra are a problem; they can t be explained using classical physics Dr. Sabry El-Taher 33

34 3. Absorption line spectrum A cool gas absorbs certain wavelengths from a continuous spectrum, leaving dark absorption lines in their place. These lines are also characteristic of the chemical composition of the gas. Dr. Sabry El-Taher 34

35 Example: Emission and Absorption Spectra of Na Dr. Sabry El-Taher 35

36 Emission Spectrum of Hydrogen 1. The Balmer Formula (1885) Joseph Balmer first noticed that the frequency of visible lines in the H atom spectrum could be reproduced by: Where n is an integer, n = 3, 4, 5 This equation accounted only for lines in the visible and near u.v. The above equation predicts that as n increases, the frequencies become more closely spaced. Dr. Sabry El-Taher 36

37 2. The Rydberg Formula (1890) Rydberg extended the Balmer s formula to cover the additional series of lines of the hydrogen spectrum outside the visible region: The modern value of the Rydberg constant, R H, is cm -1. The line spectra of atoms couldn t be explained by classical physics. Dr. Sabry El-Taher 37

38 The Bohr Model of Hydrogen Atom Bohr s general assumptions: n = 2 n = 1 1. Stationary states, exist in atoms and have well-defined energies, E n. in which orbiting electrons do not radiate energy, Transitions can occur between them, yielding light of energy: E = E n E n = hν 2. The angular momentum of the n th state n = 3 is quantized: L = mvr = nħ where n is called the Principal Quantum Number (ħ = h/2π) Dr. Sabry El-Taher 38

39 Bohr Radius The angular momentum is: L = mvr = n So the velocity is: v = n / mr But 4 e mv 2 2 = 2 πε r r So n m r e 4πε mr = 0 r = 4πε 0 2 me 2 a 0 Solving for r n 2 r n = na 0 where a 0 is called the Bohr radius. It is equal to: a 0 4πε me The ground state Hydrogen atom diameter is: Dr. Sabry El-Taher 39

40 The Hydrogen Atom Energies The classical result for the energy: E E 1 e 1 e e 2 4πε 0r 2 4πε r 4πε r = mv = n 2 = e 8πε r since 0 n 4πε n n = 2 So the energies of the stationary states are: r me or: E n = E 0 /n 2 Where E 0 = 13.6 ev. Dr. Sabry El-Taher 40

41 Transitions in the Hydrogen Atom The atom will remain in the excited state for a short time before emitting a photon and returning to a lower stationary state. In equilibrium, all hydrogen atoms exist in n = 1. Dr. Sabry El-Taher 41

42 The Bohr Model of Hydrogen Atom When excited, the electron is in a higher energy level. Excitation: The atom absorbs energy that is exactly equal to the difference between two energy levels. Emission: The atom gives off energy as a photon. Upon emission, the electron drops to a lower energy level. Each circle represents an allowed energy level for the electron. The electron may be thought of as orbiting at a fixed distance from the nucleus. Dr. Sabry El-Taher 42

43 The Bohr Model Bohr model for the H atom is capable of reproducing the energy levels given by the empirical formulas of Balmer and Rydberg. E = 2.178x10 18 J Z 2 n 2 Energy levels get closer together as n increases. at n = infinity, E = 0 Dr. Sabry El-Taher 43

44 The Bohr Model (cont.) We can use the Bohr model to predict what E is for any two energy levels E = E final E initial E = 2.178x10 18 J 1 2 n final ( 2.178x10 18 J) 1 2 n initial E = 2.178x10 18 J n final n initial Dr. Sabry El-Taher 44

45 Dr. Sabry El-Taher 45

46 The Bohr Model (cont.) Example: At what wavelength will emission from n = 4 to n = 1 for the H atom be observed? E = 2.178x10 18 J n final 1 4 n initial E = 2.178x10 18 J 1 1 = 2.04x10 18 J 16 E = 2.04x10 18 J = hc λ = 9.74x10 8 m = 97.4nm λ Dr. Sabry El-Taher 46

47 The Bohr Model (cont.) Example: What is the longest wavelength of light that will result in removal of the e - from H? E = 2.178x10 18 J n final 1 n initial E = 2.178x10 18 J( 0 1)= 2.178x10 18 J E = 2.178x10 18 J = hc λ = 9.13x10 8 m = 91.3nm λ Dr. Sabry El-Taher 47

48 Extension to Higher Z The Bohr model can be extended to any single electron system.must keep track of Z (atomic number). E = 2.178x10 18 J Z 2 n 2 Z = atomic number n = integer (1, 2,.) Examples: He + (Z = 2), Li +2 (Z = 3), etc. Dr. Sabry El-Taher 48

49 Extension to Higher Z (cont.) Example: At what wavelength will emission from n = 4 to n = 1 for the He + atom be observed? E = 2.178x10 18 J Z 2 2 E = 2.178x10 18 J 4 E = 8.16x10 18 J = hc λ ( ) 1 n final n initial Dr. Sabry El-Taher 49 ( ) = 8.16x10 18 J 16 λ = 2.43x10 8 m = 24.3nm λ H > λ He +

50 Example 1: Calculate the energy of an electron in the second energy level of a hydrogen atom. Example 2: Calculate the energy change, in joules, that occurs when an electron falls from the n i = 5 to the n f = 3 energy level in a hydrogen atom. Example 3: Calculate the frequency of the radiation released by the transition of an electron in a hydrogen atom from the n = 5 level to the n = 3 level, the transition we looked at in Example 2. Example 4: Without doing detailed calculations, determine which of the four electron transitions shown in the Figure produces the shortest-wavelength line in the hydrogen emission spectrum. Dr. Sabry El-Taher 50

51 Successes of the Bohr Theory Explained several features of the hydrogen spectrum Accounts for Balmer and other series. Predicts a value for R H that agrees with the experimental value. Gives an expression for the radius of the atom. Predicts energy levels of hydrogen atom. Gives a model of what the atom looks like and how it behaves. Can be extended to hydrogen-like atom (those with one electron, e.g. He +1, Li +2 ) Dr. Sabry El-Taher 51

52 Limitations of the Bohr Model The Bohr model was a great step in the new quantum theory, It had made three important postulates: 1) electrons exist only in discrete energy levels, and 2) Energy is absorbed as photons to excite the electron from one level to a higher energy level, and is emitted as photons in dropping to a lower energy level. 3) The angular momentum is quantized (L = mvr = nħ ). But it had its limitations. 1) Works only for single-electron ( hydrogenic ) atoms. 2) Could not account for the intensities or the fine structure 3) of the spectral lines (for example, in magnetic fields). Could not explain the binding of atoms into molecules. 4) It was a one-dimensional model (radius) that used one quantum number n to describe the distribution of electrons in an atom. Dr. Sabry El-Taher 52

53 De Broglie Waves Louis V. de Broglie( ) If a light-wave could also act like a particle, why shouldn t matter-particles also act like waves? Louis de Broglie s hypothesis stated that an object in motion behaves as both particles and waves, just as light does. A particle with mass m moving at a speed v will have a wave nature consistent with a wavelength given by the equation: λ = h h ; p mv mv = p = The quantity mv is its momentum p. The electron thus is not only a particle, but also a wave. This was confirmed in that electrons can be diffracted by crystals. Since electrons are waves, it is inappropriate to treat them only as particles, as in the Bohr model of the atom. Dr. Sabry El-Taher 53

54 de Broglie Waves in Hydrogen Atom One of Bohr s assumptions was that the angular momentum of the electron in a stationary state is quantized: mvr = nh 2π = n de Broglie assumed that the electron orbit would be stable (allowed) only if it contained an integral number of electron wavelengths. Circumference electron de Broglie wavelength Multiplying by p/2π, we find the angular momentum: Dr. Sabry El-Taher 54

55 de Broglie Waves: Experimental Evidences The similarity of the two patterns Shows that electrons behave like X-rays and display wavelike properties. In 1961, C. Jönsson, Germany, succeeded in showing double-slit interference effects for electrons by constructing very narrow slits and using relatively large distances between the slits and the observation screen. This experiment demonstrated that the same behavior occurs precisely for both light (waves) and electrons. X-ray Diffraction Electron Diffraction Electron Double-Slit Experiment Dr. Sabry El-Taher 55

56 Heisenberg's Uncertainty Principle The Uncertainty Principle is an important consequence of the wave-particle duality of matter and radiation and is inherent to the quantum description of nature Simply stated, it is impossible to know both the exact position and the exact momentum of an object simultaneously Uncertainty in position: Uncertainty in momentum: x p x h 2π x p x Werner Heisenberg ( ) Planck s constant is so small that the uncertainties implied by the principle are also too small to be observed. They are only significant in the domain of microscopic systems Dr. Sabry El-Taher 56

57 Models of the Atom Democritus Billiard Ball (450 BC) Why? Smallest indivisible chunk of matter Problem: Atoms can be ionized. Thomson Plum Pudding (1904) Why? Known that negative charges can be removed Problem: Rutherford showed positive charge was small core. Rutherford Solar System (1911) Why? Scattering showed small core. Problem: electrons should spiral into nucleus in ~10-15 sec. Dr. Sabry El-Taher 57

58 Models of the Atom Bohr fixed energy levels (1913) Why? Explains spectral lines. Problem: No reason for fixed energy levels debroglie electron standing waves (1924) Why? Explains fixed energy levels Problem: still only works for Hydrogen. Schrödinger quantum wave functions (1926) Why? Explains everything! Problem: hard to understand Dr. Sabry El-Taher 58

Preview. Atomic Physics Section 1. Section 1 Quantization of Energy. Section 2 Models of the Atom. Section 3 Quantum Mechanics

Preview. Atomic Physics Section 1. Section 1 Quantization of Energy. Section 2 Models of the Atom. Section 3 Quantum Mechanics Atomic Physics Section 1 Preview Section 1 Quantization of Energy Section 2 Models of the Atom Section 3 Quantum Mechanics Atomic Physics Section 1 TEKS The student is expected to: 8A describe the photoelectric

More information

Chapter 27 Early Quantum Theory and Models of the Atom Discovery and Properties of the electron

Chapter 27 Early Quantum Theory and Models of the Atom Discovery and Properties of the electron Chapter 27 Early Quantum Theory and Models of the Atom 27-1 Discovery and Properties of the electron Measure charge to mass ratio e/m (J. J. Thomson, 1897) When apply magnetic field only, the rays are

More information

Chapter 37 Early Quantum Theory and Models of the Atom

Chapter 37 Early Quantum Theory and Models of the Atom Chapter 37 Early Quantum Theory and Models of the Atom Units of Chapter 37 37-7 Wave Nature of Matter 37-8 Electron Microscopes 37-9 Early Models of the Atom 37-10 Atomic Spectra: Key to the Structure

More information

Constants & Atomic Data. The birth of atomic physics and quantum mechanics. debroglie s Wave Equations. Energy Calculations. λ = f = h E.

Constants & Atomic Data. The birth of atomic physics and quantum mechanics. debroglie s Wave Equations. Energy Calculations. λ = f = h E. Constants & Atomic Data The birth of atomic physics and quantum mechanics Honors Physics Don Rhine Look inside back cover of book! Speed of Light (): c = 3.00 x 10 8 m/s Elementary Charge: e - = p + =

More information

The birth of atomic physics and quantum mechanics. Honors Physics Don Rhine

The birth of atomic physics and quantum mechanics. Honors Physics Don Rhine The birth of atomic physics and quantum mechanics Honors Physics Don Rhine Constants & Atomic Data Look inside back cover of book! Speed of Light (vacuum): c = 3.00 x 10 8 m/s Elementary Charge: e - =

More information

Early Quantum Theory and Models of the Atom

Early Quantum Theory and Models of the Atom Early Quantum Theory and Models of the Atom Electron Discharge tube (circa 1900 s) There is something ( cathode rays ) which is emitted by the cathode and causes glowing Unlike light, these rays are deflected

More information

Atomic Structure Discovered. Dalton s Atomic Theory. Discovery of the Electron 10/30/2012

Atomic Structure Discovered. Dalton s Atomic Theory. Discovery of the Electron 10/30/2012 Atomic Structure Discovered Ancient Greeks Democritus (460-362 BC) - indivisible particles called atoms Prevailing argument (Plato and Aristotle) - matter is continuously and infinitely divisible John

More information

Planck s Quantum Hypothesis Blackbody Radiation

Planck s Quantum Hypothesis Blackbody Radiation Planck s Quantum Hypothesis Blackbody Radiation The spectrum of blackbody radiation has been measured(next slide); it is found that the frequency of peak intensity increases linearly with temperature.

More information

Energy levels and atomic structures lectures chapter one

Energy levels and atomic structures lectures chapter one Structure of Atom An atom is the smallest constituent unit of ordinary matter that has the properties of a element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are

More information

is the minimum stopping potential for which the current between the plates reduces to zero.

is the minimum stopping potential for which the current between the plates reduces to zero. Module 1 :Quantum Mechanics Chapter 2 : Introduction to Quantum ideas Introduction to Quantum ideas We will now consider some experiments and their implications, which introduce us to quantum ideas. The

More information

Democritus & Leucippus (~400 BC) Greek philosophers: first to propose that matter is made up of particles called atomos, the Greek word for atoms

Democritus & Leucippus (~400 BC) Greek philosophers: first to propose that matter is made up of particles called atomos, the Greek word for atoms Chemistry Ms. Ye Name Date Block The Evolution of the Atomic Model Since atoms are too small to see even with a very powerful microscope, scientists rely upon indirect evidence and models to help them

More information

The Photoelectric Effect

The Photoelectric Effect Stellar Astrophysics: The Interaction of Light and Matter The Photoelectric Effect Methods of electron emission Thermionic emission: Application of heat allows electrons to gain enough energy to escape

More information

Early Quantum Theory & Models of the Atom (Ch 27) Discovery of electron. Blackbody Radiation. Blackbody Radiation. J. J. Thomson ( )

Early Quantum Theory & Models of the Atom (Ch 27) Discovery of electron. Blackbody Radiation. Blackbody Radiation. J. J. Thomson ( ) Early Quantum Theory & Models of the Atom (Ch 27) Discovery of electron Modern physics special relativity quantum theory J. J. Thomson (1856-1940) measured e/m directly set-up was similar to mass spectrometer

More information

Quantum Physics and Atomic Models Chapter Questions. 1. How was it determined that cathode rays possessed a negative charge?

Quantum Physics and Atomic Models Chapter Questions. 1. How was it determined that cathode rays possessed a negative charge? Quantum Physics and Atomic Models Chapter Questions 1. How was it determined that cathode rays possessed a negative charge? 2. J. J. Thomson found that cathode rays were really particles, which were subsequently

More information

PSI AP Physics How was it determined that cathode rays possessed a negative charge?

PSI AP Physics How was it determined that cathode rays possessed a negative charge? PSI AP Physics 2 Name Chapter Questions 1. How was it determined that cathode rays possessed a negative charge? 2. J. J. Thomson found that cathode rays were really particles, which were subsequently named

More information

Chapter 7: The Quantum-Mechanical Model of the Atom

Chapter 7: The Quantum-Mechanical Model of the Atom C h e m i s t r y 1 A : C h a p t e r 7 P a g e 1 Chapter 7: The Quantum-Mechanical Model of the Atom Homework: Read Chapter 7. Work out sample/practice exercises Check for the MasteringChemistry.com assignment

More information

Chapter 37 Early Quantum Theory and Models of the Atom. Copyright 2009 Pearson Education, Inc.

Chapter 37 Early Quantum Theory and Models of the Atom. Copyright 2009 Pearson Education, Inc. Chapter 37 Early Quantum Theory and Models of the Atom Planck s Quantum Hypothesis; Blackbody Radiation Photon Theory of Light and the Photoelectric Effect Energy, Mass, and Momentum of a Photon Compton

More information

1. Historical perspective

1. Historical perspective Atomic and Molecular Physics/Lecture notes presented by Dr. Fouad Attia Majeed/Third year students/college of Education (Ibn Hayyan)/Department of Physics/University of Babylon. 1. Historical perspective

More information

Semiconductor Physics and Devices

Semiconductor Physics and Devices Introduction to Quantum Mechanics In order to understand the current-voltage characteristics, we need some knowledge of electron behavior in semiconductor when the electron is subjected to various potential

More information

Quantum and Atomic Physics - Multiple Choice

Quantum and Atomic Physics - Multiple Choice PSI AP Physics 2 Name 1. The Cathode Ray Tube experiment is associated with: (A) J. J. Thomson (B) J. S. Townsend (C) M. Plank (D) A. H. Compton 2. The electron charge was measured the first time in: (A)

More information

Physics 1C. Modern Physics Lecture

Physics 1C. Modern Physics Lecture Physics 1C Modern Physics Lecture "I ask you to look both ways. For the road to a knowledge of the stars leads through the atom; and important knowledge of the atom has been reached through the stars."

More information

CHEMISTRY Topic #1: Atomic Structure and Nuclear Chemistry Fall 2017 Dr. Susan Findlay See Exercises 3.1 to 3.3

CHEMISTRY Topic #1: Atomic Structure and Nuclear Chemistry Fall 2017 Dr. Susan Findlay See Exercises 3.1 to 3.3 CHEMISTRY 1000 Topic #1: Atomic Structure and Nuclear Chemistry Fall 2017 Dr. Susan Findlay See Exercises 3.1 to 3.3 Light: Wave? Particle? Both! Modern models of the atom were derived by studying the

More information

Stellar Astrophysics: The Interaction of Light and Matter

Stellar Astrophysics: The Interaction of Light and Matter Stellar Astrophysics: The Interaction of Light and Matter The Photoelectric Effect Methods of electron emission Thermionic emission: Application of heat allows electrons to gain enough energy to escape

More information

12/04/2012. Models of the Atom. Quantum Physics versus Classical Physics The Thirty-Year War ( )

12/04/2012. Models of the Atom. Quantum Physics versus Classical Physics The Thirty-Year War ( ) Quantum Physics versus Classical Physics The Thirty-Year War (1900-1930) Interactions between Matter and Radiation Models of the Atom Bohr s Model of the Atom Planck s Blackbody Radiation Models of the

More information

Lecture 11 Atomic Structure

Lecture 11 Atomic Structure Lecture 11 Atomic Structure Earlier in the semester, you read about the discoveries that lead to the proposal of the nuclear atom, an atom of atomic number Z, composed of a positively charged nucleus surrounded

More information

Chapter 7 Atomic Structure -1 Quantum Model of Atom. Dr. Sapna Gupta

Chapter 7 Atomic Structure -1 Quantum Model of Atom. Dr. Sapna Gupta Chapter 7 Atomic Structure -1 Quantum Model of Atom Dr. Sapna Gupta The Electromagnetic Spectrum The electromagnetic spectrum includes many different types of radiation which travel in waves. Visible light

More information

Professor K. Atomic structure

Professor K. Atomic structure Professor K Atomic structure Review Reaction- the formation and breaking of chemical bonds Bond- a transfer or sharing of electrons Electrons Abbreviated e - What are they? How were they discovered? Early

More information

History of the Atomic Model

History of the Atomic Model Chapter 5 Lecture Chapter 5 Electronic Structure and Periodic Trends 5.1 Electromagnetic Radiation Learning Goal Compare the wavelength, frequency, and energy of electromagnetic radiation. Fifth Edition

More information

Chapter 28. Atomic Physics

Chapter 28. Atomic Physics Chapter 28 Atomic Physics Sir Joseph John Thomson J. J. Thomson 1856-1940 Discovered the electron Did extensive work with cathode ray deflections 1906 Nobel Prize for discovery of electron Early Models

More information

Atomic Theory. Early models

Atomic Theory. Early models Atomic Theory Early models Ancient Greece Late 18 th century 4 elements Earth, Water, Wind, Fire: Matter is made up in different combinations of these 4 elements. First atom proposed by Democritus (Greek)

More information

Lecture PowerPoints. Chapter 27 Physics: Principles with Applications, 7th edition Giancoli

Lecture PowerPoints. Chapter 27 Physics: Principles with Applications, 7th edition Giancoli Lecture PowerPoints Chapter 27 Physics: Principles with Applications, 7th edition Giancoli This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching

More information

Chapter 27 Lecture Notes

Chapter 27 Lecture Notes Chapter 27 Lecture Notes Physics 2424 - Strauss Formulas: λ P T = 2.80 10-3 m K E = nhf = nhc/λ fλ = c hf = K max + W 0 λ = h/p λ - λ = (h/mc)(1 - cosθ) 1/λ = R(1/n 2 f - 1/n 2 i ) Lyman Series n f = 1,

More information

CHAPTER 27 Quantum Physics

CHAPTER 27 Quantum Physics CHAPTER 27 Quantum Physics Units Discovery and Properties of the Electron Planck s Quantum Hypothesis; Blackbody Radiation Photon Theory of Light and the Photoelectric Effect Energy, Mass, and Momentum

More information

Structure of the Atom. Thomson s Atomic Model. Knowledge of atoms in Experiments of Geiger and Marsden 2. Experiments of Geiger and Marsden

Structure of the Atom. Thomson s Atomic Model. Knowledge of atoms in Experiments of Geiger and Marsden 2. Experiments of Geiger and Marsden CHAPTER 4 Structure of the Atom 4.1 The Atomic Models of Thomson and Rutherford 4. Rutherford Scattering 4.3 The Classic Atomic Model 4.4 The Bohr Model of the Hydrogen Atom 4.5 Successes & Failures of

More information

Chemistry is in the electrons

Chemistry is in the electrons Chemistry is in the electrons Electronic structure arrangement of electrons in atom Two parameters: Energy Position The popular image of the atom is incorrect: electrons are not miniature planets orbiting

More information

Ch 7 Quantum Theory of the Atom (light and atomic structure)

Ch 7 Quantum Theory of the Atom (light and atomic structure) Ch 7 Quantum Theory of the Atom (light and atomic structure) Electromagnetic Radiation - Electromagnetic radiation consists of oscillations in electric and magnetic fields. The oscillations can be described

More information

Chapter 6. Quantum Theory and the Electronic Structure of Atoms Part 1

Chapter 6. Quantum Theory and the Electronic Structure of Atoms Part 1 Chapter 6 Quantum Theory and the Electronic Structure of Atoms Part 1 The nature of light Quantum theory Topics Bohr s theory of the hydrogen atom Wave properties of matter Quantum mechanics Quantum numbers

More information

WAVE NATURE OF LIGHT

WAVE NATURE OF LIGHT WAVE NATURE OF LIGHT Light is electromagnetic radiation, a type of energy composed of oscillating electric and magnetic fields. The fields oscillate perpendicular to each other. In vacuum, these waves

More information

Physics 1C Lecture 29A. Finish off Ch. 28 Start Ch. 29

Physics 1C Lecture 29A. Finish off Ch. 28 Start Ch. 29 Physics 1C Lecture 29A Finish off Ch. 28 Start Ch. 29 Particle in a Box Let s consider a particle confined to a one-dimensional region in space. Following the quantum mechanics approach, we need to find

More information

Particle nature of light & Quantization

Particle nature of light & Quantization Particle nature of light & Quantization A quantity is quantized if its possible values are limited to a discrete set. An example from classical physics is the allowed frequencies of standing waves on a

More information

Models of the Atom. Spencer Clelland & Katelyn Mason

Models of the Atom. Spencer Clelland & Katelyn Mason Models of the Atom Spencer Clelland & Katelyn Mason First Things First Electrons were accepted to be part of the atom structure by scientists in the1900 s. The first model of the atom was visualized as

More information

3. Particle nature of matter

3. Particle nature of matter 3. Particle nature of matter 3.1 atomic nature of matter Democrit(us) 470-380 B.C.: there is only atoms and empty space, everything else is mere opinion (atoms are indivisible) Dalton (chemist) 180: chemical

More information

Astronomy The Nature of Light

Astronomy The Nature of Light Astronomy The Nature of Light A. Dayle Hancock adhancock@wm.edu Small 239 Office hours: MTWR 10-11am Measuring the speed of light Light is an electromagnetic wave The relationship between Light and temperature

More information

1 The Cathode Rays experiment is associated. with: Millikan A B. Thomson. Townsend. Plank Compton

1 The Cathode Rays experiment is associated. with: Millikan A B. Thomson. Townsend. Plank Compton 1 The Cathode Rays experiment is associated with: A B C D E Millikan Thomson Townsend Plank Compton 1 2 The electron charge was measured the first time in: A B C D E Cathode ray experiment Photoelectric

More information

Learning Objectives and Worksheet I. Chemistry 1B-AL Fall 2016

Learning Objectives and Worksheet I. Chemistry 1B-AL Fall 2016 Learning Objectives and Worksheet I Chemistry 1B-AL Fall 2016 Lectures (1 2) Nature of Light and Matter, Quantization of Energy, and the Wave Particle Duality Read: Chapter 12, Pages: 524 526 Supplementary

More information

Greek Philosophers (cont.)

Greek Philosophers (cont.) Greek Philosophers (cont.) Many ancient scholars believed matter was composed of such things as earth, water, air, and fire. Many believed matter could be endlessly divided into smaller and smaller pieces.

More information

Physical Electronics. First class (1)

Physical Electronics. First class (1) Physical Electronics First class (1) Bohr s Model Why don t the electrons fall into the nucleus? Move like planets around the sun. In circular orbits at different levels. Amounts of energy separate one

More information

LIGHT. Question. Until very recently, the study of ALL astronomical objects, outside of the Solar System, has been with telescopes observing light.

LIGHT. Question. Until very recently, the study of ALL astronomical objects, outside of the Solar System, has been with telescopes observing light. LIGHT Question Until very recently, the study of ALL astronomical objects, outside of the Solar System, has been with telescopes observing light. What kind of information can we get from light? 1 Light

More information

CHAPTER 3 The Experimental Basis of Quantum Theory

CHAPTER 3 The Experimental Basis of Quantum Theory CHAPTER 3 The Experimental Basis of Quantum Theory 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 Discovery of the X Ray and the Electron Determination of Electron Charge Line Spectra Quantization As far as I can

More information

Chapter 1 Early Quantum Phenomena

Chapter 1 Early Quantum Phenomena Chapter Early Quantum Phenomena... 8 Early Quantum Phenomena... 8 Photo- electric effect... Emission Spectrum of Hydrogen... 3 Bohr s Model of the atom... 4 De Broglie Waves... 7 Double slit experiment...

More information

Chapter 1. From Classical to Quantum Mechanics

Chapter 1. From Classical to Quantum Mechanics Chapter 1. From Classical to Quantum Mechanics Classical Mechanics (Newton): It describes the motion of a classical particle (discrete object). dp F ma, p = m = dt dx m dt F: force (N) a: acceleration

More information

Quantum Theory of the Atom

Quantum Theory of the Atom The Wave Nature of Light Quantum Theory of the Atom Electromagnetic radiation carries energy = radiant energy some forms are visible light, x rays, and radio waves Wavelength ( λ) is the distance between

More information

The Photoelectric Effect

The Photoelectric Effect The Photoelectric Effect Light can strike the surface of some metals causing an electron to be ejected No matter how brightly the light shines, electrons are ejected only if the light has sufficient energy

More information

Chapter 7. The Quantum- Mechanical Model of the Atom. Chapter 7 Lecture Lecture Presentation. Sherril Soman Grand Valley State University

Chapter 7. The Quantum- Mechanical Model of the Atom. Chapter 7 Lecture Lecture Presentation. Sherril Soman Grand Valley State University Chapter 7 Lecture Lecture Presentation Chapter 7 The Quantum- Mechanical Model of the Atom Sherril Soman Grand Valley State University The Beginnings of Quantum Mechanics Until the beginning of the twentieth

More information

The Development of Atomic Theory

The Development of Atomic Theory The Development of Atomic Theory Democritus (400 BC) John Dalton (1803) J.J. Thomson (1897) Ernest Rutherford (1911) James Chadwick (1932) - suggested that matter is composed of indivisible particles called

More information

CHEMISTRY Matter and Change

CHEMISTRY Matter and Change CHEMISTRY Matter and Change Chapter 5: Electrons in Atoms 5 Section 5.1 Section Section 5.3 Table Of Contents Light and Quantized Energy Electron Configuration Compare the wave and particle natures of

More information

Electrons in Atoms. Section 5.1 Light and Quantized Energy Section 5.2 Quantum Theory and the Atom Section 5.3 Electron Configuration

Electrons in Atoms. Section 5.1 Light and Quantized Energy Section 5.2 Quantum Theory and the Atom Section 5.3 Electron Configuration Electrons in Atoms Section 5.1 Light and Quantized Energy Section 5.2 Quantum Theory and the Atom Section 5.3 Electron Configuration Click a hyperlink or folder tab to view the corresponding slides. Exit

More information

CHEMISTRY. Chapter 6 Electronic Structure of Atoms

CHEMISTRY. Chapter 6 Electronic Structure of Atoms CHEMISTRY The Central Science 8 th Edition Chapter 6 Electronic Structure of Atoms Kozet YAPSAKLI Who are these men? Ancient Philosophy Who: Aristotle, Democritus When: More than 2000 years ago Where:

More information

Where are we? Check-In

Where are we? Check-In Where are we? Check-In ü Building Blocks of Matter ü Moles, molecules, grams, gases, ü The Bohr Model solutions, and percent composition Coulomb s Law ü Empirical and Molecular formulas Photoelectron Spectroscopy

More information

Accounts for certain objects being colored. Used in medicine (examples?) Allows us to learn about structure of the atom

Accounts for certain objects being colored. Used in medicine (examples?) Allows us to learn about structure of the atom 1.1 Interaction of Light and Matter Accounts for certain objects being colored Used in medicine (examples?) 1.2 Wavelike Properties of Light Wavelength, : peak to peak distance Amplitude: height of the

More information

QUANTUM MECHANICS Chapter 12

QUANTUM MECHANICS Chapter 12 QUANTUM MECHANICS Chapter 12 Colours which appear through the Prism are to be derived from the Light of the white one Sir Issac Newton, 1704 Electromagnetic Radiation (prelude) FIG Electromagnetic Radiation

More information

CHAPTER 3 Prelude to Quantum Theory. Observation of X Rays. Thomson s Cathode-Ray Experiment. Röntgen s X-Ray Tube

CHAPTER 3 Prelude to Quantum Theory. Observation of X Rays. Thomson s Cathode-Ray Experiment. Röntgen s X-Ray Tube CHAPTER Prelude to Quantum Theory.1 Discovery of the X Ray and the Electron. Determination of Electron Charge. Line Spectra.4 Quantization.5 Blackbody Radiation.6 Photoelectric Effect.7 X-Ray Production.8

More information

We also find the development of famous Schrodinger equation to describe the quantization of energy levels of atoms.

We also find the development of famous Schrodinger equation to describe the quantization of energy levels of atoms. Lecture 4 TITLE: Quantization of radiation and matter: Wave-Particle duality Objectives In this lecture, we will discuss the development of quantization of matter and light. We will understand the need

More information

THE NATURE OF THE ATOM. alpha particle source

THE NATURE OF THE ATOM. alpha particle source chapter THE NATURE OF THE ATOM www.tutor-homework.com (for tutoring, homework help, or help with online classes) Section 30.1 Rutherford Scattering and the Nuclear Atom 1. Which model of atomic structure

More information

Atomic Theory. Developing the Nuclear Model of the Atom. Saturday, January 20, 18

Atomic Theory. Developing the Nuclear Model of the Atom. Saturday, January 20, 18 Atomic Theory Developing the Nuclear Model of the Atom Democritus Theory: Atom, the indivisible particle c. 300 BC Democritus Problem: No scientific evidence c. 300 BC Dalton Theory: The solid sphere model

More information

Chapter 39. Particles Behaving as Waves

Chapter 39. Particles Behaving as Waves Chapter 39 Particles Behaving as Waves 39.1 Electron Waves Light has a dual nature. Light exhibits both wave and particle characteristics. Louis de Broglie postulated in 1924 that if nature is symmetric,

More information

Lecture 6 - Atomic Structure. Chem 103, Section F0F Unit II - Quantum Theory and Atomic Structure Lecture 6. Lecture 6 - Introduction

Lecture 6 - Atomic Structure. Chem 103, Section F0F Unit II - Quantum Theory and Atomic Structure Lecture 6. Lecture 6 - Introduction Chem 103, Section F0F Unit II - Quantum Theory and Atomic Structure Lecture 6 Light and other forms of electromagnetic radiation Light interacting with matter The properties of light and matter Lecture

More information

Atomic Structure. Standing Waves x10 8 m/s. (or Hz or 1/s) λ Node

Atomic Structure. Standing Waves x10 8 m/s. (or Hz or 1/s) λ Node Atomic Structure Topics: 7.1 Electromagnetic Radiation 7.2 Planck, Einstein, Energy, and Photons 7.3 Atomic Line Spectra and Niels Bohr 7.4 The Wave Properties of the Electron 7.5 Quantum Mechanical View

More information

Electron Arrangement - Part 1

Electron Arrangement - Part 1 Brad Collins Electron Arrangement - Part 1 Chapter 8 Some images Copyright The McGraw-Hill Companies, Inc. Properties of Waves Wavelength (λ) is the distance between identical points on successive waves.

More information

LECTURE # 19 Dennis Papadopoulos End of Classical Physics Quantization Bohr Atom Chapters 38 39

LECTURE # 19 Dennis Papadopoulos End of Classical Physics Quantization Bohr Atom Chapters 38 39 PHYS 270-SPRING 2011 LECTURE # 19 Dennis Papadopoulos End of Classical Physics Quantization Bohr Atom Chapters 38 39 April 14, 2011 1 HOW TO MEASURE SPECTRA Spectroscopy: Unlocking the Structure of Atoms

More information

Light & Matter Interactions

Light & Matter Interactions Light & Matter Interactions. Spectral Lines. Kirchoff's Laws 2. Inside atoms 3. Classical Atoms 4. The Bohr Model 5. Lowest energy 6. Kirchoff's laws, again 2. Quantum Theory. The Photoelectric Effect

More information

RED. BLUE Light. Light-Matter

RED. BLUE Light.   Light-Matter 1 Light-Matter This experiment demonstrated that light behaves as a wave. Essentially Thomas Young passed a light of a single frequency ( colour) through a pair of closely spaced narrow slits and on the

More information

Chapter 6 Electronic structure of atoms

Chapter 6 Electronic structure of atoms Chapter 6 Electronic structure of atoms light photons spectra Heisenberg s uncertainty principle atomic orbitals electron configurations the periodic table 6.1 The wave nature of light Visible light is

More information

Atomic Models. 1) Students will be able to describe the evolution of atomic models.

Atomic Models. 1) Students will be able to describe the evolution of atomic models. Atomic Models 1) Students will be able to describe the evolution of atomic models. 2) Students will be able to describe the role of experimental evidence in changing models of the atom. 3) Students will

More information

4/14/2015. Models of the Atom. Quantum Physics versus Classical Physics The Thirty-Year War ( ) Classical Model of Atom

4/14/2015. Models of the Atom. Quantum Physics versus Classical Physics The Thirty-Year War ( ) Classical Model of Atom Quantum Physics versus Classical Physics The Thirty-Year War (1900-1930) Models of the Atom Interactions between Matter and Radiation Models of the Atom Bohr s Model of the Atom Planck s Blackbody Radiation

More information

The atom cont. +Investigating EM radiation

The atom cont. +Investigating EM radiation The atom cont. +Investigating EM radiation Announcements: First midterm is 7:30pm on Sept 26, 2013 Will post a past midterm exam from 2011 today. We are covering Chapter 3 today. (Started on Wednesday)

More information

Chapter 38 and Chapter 39

Chapter 38 and Chapter 39 Chapter 38 and Chapter 39 State of 19th and very early 20th century physics: Light: 1. E&M Maxwell s equations > waves; J. J. Thompson s double slit experiment with light 2. Does light need a medium? >

More information

Modern Physics for Scientists and Engineers International Edition, 4th Edition

Modern Physics for Scientists and Engineers International Edition, 4th Edition Modern Physics for Scientists and Engineers International Edition, 4th Edition http://optics.hanyang.ac.kr/~shsong Review: 1. THE BIRTH OF MODERN PHYSICS 2. SPECIAL THEORY OF RELATIVITY 3. THE EXPERIMENTAL

More information

Quantum Theory of Light

Quantum Theory of Light King Saud University College of Applied Studies and Community Service Department of Natural Sciences Quantum Theory of Light General Physics II PHYS 111 Nouf Alkathran nalkathran@ksu.edu.sa Outline Definition

More information

Chapter 7. The Quantum Mechanical Model of the Atom

Chapter 7. The Quantum Mechanical Model of the Atom Chapter 7 The Quantum Mechanical Model of the Atom The Nature of Light:Its Wave Nature Light is a form of electromagnetic radiation composed of perpendicular oscillating waves, one for the electric field

More information

9/23/2012. Democritus 400 B.C. Greek philosopher Proposed that all materials are made from atoms. Coined Greek word atmos, meaning indivisible.

9/23/2012. Democritus 400 B.C. Greek philosopher Proposed that all materials are made from atoms. Coined Greek word atmos, meaning indivisible. Mr. Sudbury Atoms are too small to see with your eyes. Atoms are too small to see with the most powerful microscopes. Scientist use models to explain atoms. A scientific model is an representation containing

More information

The Bohr Model of the Atom

The Bohr Model of the Atom Unit 4: The Bohr Model of the Atom Properties of light Before the 1900 s, light was thought to behave only as a wave. Light is a type of electromagnetic radiation - a form of energy that exhibits wave

More information

Physics. Light Quanta

Physics. Light Quanta Physics Light Quanta Quantum Theory Is light a WAVE or a PARTICLE? Particle tiny object like a bullet, has mass and travels in straight lines unless a force acts upon it Waves phenomena that extend in

More information

Einstein. Quantum Physics at a glance. Planck s Hypothesis (blackbody radiation) (ultraviolet catastrophe) Quantized Energy

Einstein. Quantum Physics at a glance. Planck s Hypothesis (blackbody radiation) (ultraviolet catastrophe) Quantized Energy Quantum Physics at a glance Quantum Physics deals with the study of light and particles at atomic and smaller levels. Planck s Hypothesis (blackbody radiation) (ultraviolet catastrophe) Quantized Energy

More information

The Nature of Light. Chapter Five

The Nature of Light. Chapter Five The Nature of Light Chapter Five Guiding Questions 1. How fast does light travel? How can this speed be measured? 2. Why do we think light is a wave? What kind of wave is it? 3. How is the light from an

More information

Chapter 28. Atomic Physics

Chapter 28. Atomic Physics Chapter 28 Atomic Physics Quantum Numbers and Atomic Structure The characteristic wavelengths emitted by a hot gas can be understood using quantum numbers. No two electrons can have the same set of quantum

More information

Electronic structure the number of electrons in an atom as well as the distribution of electrons around the nucleus and their energies

Electronic structure the number of electrons in an atom as well as the distribution of electrons around the nucleus and their energies Chemistry: The Central Science Chapter 6: Electronic Structure of Atoms Electronic structure the number of electrons in an atom as well as the distribution of electrons around the nucleus and their energies

More information

Exam 2 Development of Quantum Mechanics

Exam 2 Development of Quantum Mechanics PHYS40 (Spring 00) Riq Parra Exam # (Friday, April 1 th, 00) Exam Development of Quantum Mechanics Do NOT write your name on this exam. Write your class ID number on the top right hand corner of each problem

More information

Properties of Light. Arrangement of Electrons in Atoms. The Development of a New Atomic Model. Electromagnetic Radiation CHAPTER 4

Properties of Light. Arrangement of Electrons in Atoms. The Development of a New Atomic Model. Electromagnetic Radiation CHAPTER 4 CHAPTER 4 Arrangement of Electrons in Atoms The Development of a New Atomic Model The Rutherford model was a great improvement over the Thomson model of the atom. But, there was one major question that

More information

like firing a 16 shell at a piece of tissue paper and seeing it bounce back. - E Rutherford

like firing a 16 shell at a piece of tissue paper and seeing it bounce back. - E Rutherford Black body radiation [const.] λ max = T E radiated surf. area Planck E f hf = T E W KE 4 ROY G BIV Einstein Photo-electric effect- Photons Thompson electron identification B + F v R +q 2 mv F= =qvb=f R

More information

Chapter 6 - Electronic Structure of Atoms

Chapter 6 - Electronic Structure of Atoms Chapter 6 - Electronic Structure of Atoms 6.1 The Wave Nature of Light To understand the electronic structure of atoms, one must understand the nature of electromagnetic radiation Visible light is an example

More information

Topics Covered in Chapter. Light and Other Electromagnetic Radiation. A Subatomic Interlude II. A Subatomic Interlude. A Subatomic Interlude III

Topics Covered in Chapter. Light and Other Electromagnetic Radiation. A Subatomic Interlude II. A Subatomic Interlude. A Subatomic Interlude III Light and Other Electromagnetic Radiation Topics Covered in Chapter 1.Structure of Atoms 2.Origins of Electromagnetic Radiation 3.Objects with Different Temperature and their Electromagnetic Radiation

More information

Light and Other Electromagnetic Radiation

Light and Other Electromagnetic Radiation Light and Other Electromagnetic Radiation 1 Topics Covered in Chapter 1.Structure of Atoms 2.Origins of Electromagnetic Radiation 3.Objects with Different Temperature and their Electromagnetic Radiation

More information

Chapter 5. The Electromagnetic Spectrum. What is visible light? What is visible light? Which of the following would you consider dangerous?

Chapter 5. The Electromagnetic Spectrum. What is visible light? What is visible light? Which of the following would you consider dangerous? Which of the following would you consider dangerous? X-rays Radio waves Gamma rays UV radiation Visible light Microwaves Infrared radiation Chapter 5 Periodicity and Atomic Structure 2 The Electromagnetic

More information

The Duality of Light. Electromagnetic Radiation. Light as a Wave

The Duality of Light. Electromagnetic Radiation. Light as a Wave In this unit, you will be introduced to the dual nature of light, the quantum theory and Bohr s planetary atomic model. The planetary model was an improvement on the nuclear model and attempted to answer

More information

CHAPTER 3 The Experimental Basis of Quantum

CHAPTER 3 The Experimental Basis of Quantum CHAPTER 3 The Experimental Basis of Quantum 3.1 Discovery of the X Ray and the Electron 3.2 Determination of Electron Charge 3.3 Line Spectra 3.4 Quantization 3.5 Blackbody Radiation 3.6 Photoelectric

More information

Discovery of the Atomic Nucleus. Conceptual Physics 11 th Edition. Discovery of the Electron. Discovery of the Atomic Nucleus

Discovery of the Atomic Nucleus. Conceptual Physics 11 th Edition. Discovery of the Electron. Discovery of the Atomic Nucleus Conceptual Physics 11 th Edition Chapter 32: THE ATOM AND THE QUANTUM Discovery of the Atomic Nucleus These alpha particles must have hit something relatively massive but what? Rutherford reasoned that

More information

Physics: Quanta to Quarks Option (99.95 ATAR)

Physics: Quanta to Quarks Option (99.95 ATAR) HSC Physics Year 2016 Mark 95.00 Pages 22 Published Jan 15, 2017 Physics: Quanta to Quarks Option (99.95 ATAR) By Edward (99.95 ATAR) Powered by TCPDF (www.tcpdf.org) Your notes author, Edward. Edward

More information

Physics 280 Quantum Mechanics Lecture

Physics 280 Quantum Mechanics Lecture Spring 2015 1 1 Department of Physics Drexel University August 3, 2016 Objectives Review Early Quantum Mechanics Objectives Review Early Quantum Mechanics Schrödinger s Wave Equation Objectives Review

More information

Electronic structure of atoms

Electronic structure of atoms Chapter 1 Electronic structure of atoms light photons spectra Heisenberg s uncertainty principle atomic orbitals electron configurations the periodic table 1.1 The wave nature of light Much of our understanding

More information