Chapter 39. Particles Behaving as Waves
|
|
- Horatio Cooper
- 6 years ago
- Views:
Transcription
1 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, then all forms of matter should exhibit wave properties! If a particle of matter acts like a wave, it should have a frequency and a wavelength associated with it. De Broglie postulated that a free particle with rest mass m, moving with speed v, should have a wavelength λ related to its linear momentum p by! = h p where p = m v p = " m v (nonrelativistic particle) (relativistic particle) Furthermore, in analogy with photons, the frequency f of the waves we associate with a moving particle of mass m is 1
2 f = E h where E is the energy of the material particle. For his prediction of the wave nature of electrons, Louis de Broglie was awarded the Nobel Prize in physics in Under the proper conditions, then, every stream of particles will produce an interference or diffraction pattern. Each body whether an electron, a proton, an atom, a soccer ball, a planet, or star has a wave associated with it with a wavelength that is related to its momentum by the above formula. A body of large mass and ordinary speed has such a small wavelength that interference and diffraction effects are negligible. But for smaller particles like electrons, diffraction can be appreciable. 2
3 The Electron Microscope An electron microscope makes practical use of the wave nature of electrons. The wavelength of electron beams is typically thousands of times shorter than the wavelength of visible light, so the electron microscope is able to distinguish detail not visible with optical microscopes. 3
4 39.2 The Nuclear Atom and Atomic Spectra 4
5 Rutherford s Exploration of the Atom 5
6 The Failure of Classical Physics 6
7 39.3 Energy Levels and The Bohr Model of the Atom 7
8 The Bohr Model of the Hydrogen Atom Niels Bohr postulated that each energy level of a hydrogen atom corresponds to a specific stable circular orbit of the electron around the nucleus. He further postulated that an electron in such an orbit does not radiate (contrary to classical physics). Instead, an atom radiates energy only when an electron makes a transition from an orbit of energy E i to a different orbit with lower energy E f, emitting a photon of energy hf = E i E f in the process. 8
9 The basic assumptions are: 1. The electron moves in a circular orbit about the proton interacting via the Coulomb force. Use classical mechanics to treat the motion of the electron around the proton: " F c = ma c divide by 2 to obtain k(e)(e) r 2 = m v2 r 1 2 m ev 2 = ke2 2r 9
10 2. Electromagnetic radiation (or a photon) is emitted when the electron jumps from a more energetic initial state (with energy E i ) to a less energetic final state (with energy E f ). The frequency f of the emitted radiation is given by h f = E i " E f 3. The allowed orbits for the electron are those for which the orbital angular momentum of the electron satisfies the relation m e v r = n h 2" where n is called the principal quantum number and n = 1, 2, 3, 4, 4. The energy E of the electron when it is in an allowed orbit of radius r or principal quantum number n is 10
11 E = KE +U electric = 1 2 m ev 2 + k(e)("e) r Combining the boxed equations above yields the following results for the allowed orbits of the electron around the proton, for the allowed energies of the electron as it orbits around the proton, AND the speed of an electron around the proton: where E n = " 13.6eV r n 2 n = a o n 2 v n = 2 " k e2 h 1 n a o = h 2 4 " 2 2 (radius of first Bohr orbit) k m e e That is, the values of the radii and of the energy of the electron are quantized. The state of the electron corresponding to the lowest allowed energy is called the ground state. n = 1: ground state or first Bohr orbit r 1 = a o = nm E 1 = "13.6 ev ground state energy 11
12 n = 2: first excited state or the second Bohr orbit r 2 = 4 a o = nm E 2 = " 13.6eV = "3.40 ev 4 n = 3: second excited state or third Bohr orbit r 3 = 9a o = nm E 3 = " 13.6eV = "1.51 ev 9 and so on Comments: 13.6 ev 1. The negative sign in E n = " means that the n 2 electron is bound to the proton. The electron is not free 2. n = " # E " = 0, represents the state when the electron is completely removed from the atom. Hence the minimum energy required to ionize the hydrogen atom when it is in the ground state is 13.6 ev and is called the ionization energy. 3. When an electron jumps (or undergoes a quantum transition ) from an orbit with higher energy to an orbit with lower energy, the atom emits a photon of frequency f given by 12
13 h f = E i " E f #"13.6 ev h f = % 2 $ n i & # ( " % ' $ "13.6 ev n f 2 # h f = 13.6 ev 1 2 n " 1 & % 2 ( $ f n i ' & ( ' where n i > n f. if n f = 1: Lyman series n i = 2, 3, 4, 5, (UV) # h f = 13.6 ev 1 1 " 1 & % 2 2 ( $ n i ' if n f = 2: Balmer series n i = 3, 4, 5, (Visible) # h f = 13.6 ev 1 2 " 1 & % 2 2 ( $ n i ' if n f = 3: Paschen series n i = 4, 5, 6, 7, (IR) # h f = 13.6 ev 1 3 " 1 & % 2 2 ( $ n i ' 13
14 14
15 Explanation of Quantized Energy Levels 1. Why electrons occupy only discrete levels is understood by considering the electron to be a wave, not a particle. 2. A Bohr orbit exists where an electron wave closes on itself constructively. An orbiting electron forms a standing wave only when the circumference of its orbit is equal to a whole-number multiple of wavelengths. 3. The electron wave is spread out in three-dimensions so one speaks of electron clouds. The Bohr theory of the hydrogen atom was successful when applied to hydrogen-like atoms (atoms containing only one electron). His theory breaks down when applied 15
16 to more complex atoms, and that is where the theory of quantum mechanics developed by Schroedinger, Heisenberg, Born, etc does very well in yielding results that agree with experimental data The LASER LASER: This is an acronym meaning Light Amplification by Stimulated Emission of Radiation. The first laser (ruby laser) was built by Maiman in 1960 here in California. Consider the excitation of atoms in a medium (solid, liquid, or gas) by incoming photons of the right energy. 16
17 Spontaneous Emission of Radiation This process refers to the case when an excited atom (with an electron in an orbit with a higher energy than the level it would ordinarily occupy) is left alone and emits the extra energy via electronic transitions to lower energy levels. That is, If all excited atoms are left alone, they will emit the extra energy in due time spontaneously! Stimulated Emission of Radiation You actually do not have to wait for the excited atom to emit its extra energy. You can stimulate the atom to emit the extra energy by simply shooting a photon at it of the right energy. That is, 17
18 Notice that you send in one photon and one excited atom and you end up with two photons and an atom in its ground state (de-excited). This process corresponds to light amplification! All lasers have: 1. an excitation source. This could be a provided by an electric current, a flashlight, or another laser. 2. an active medium where the laser light is generated. The active medium could be a solid, a liquid, or a gas. 3. at least two mirrors to provide the feedback mechanism. One of the mirrors needs to be partially transmitting to let the laser light out. 18
19 39.5 Continuous Spectra - Blackbody Radiation and Planck s Theory A. Thermal radiation is the radiation emitted by a body as a result of its non-zero temperature on its surface. Emission line spectra come from matter in the gaseous state, in which the atoms are so apart from one another that interactions between them are negligible. By contrast, a heated solid or liquid (in which atoms are close to each other) nearly always emits radiation with a continuous distribution of wavelengths. A blackbody is a body that has a surface that absorbs all radiation incident upon it. All blackbodies at the same temperature T emit thermal radiation with the same spectrum. 19
20 The total energy emitted per unit time, per unit area (intensity), from a blackbody with an absolute temperature T on its surface is given by the Stefan- Boltzmann law: I total = % & 2 " h c 2 ' T 4 # 5 e hc /kt $1 0 ( ) d# = The emitted intensity increases rapidly with increasing temperature. The value in SI units of the Stefan- Boltzmann constant! equals 5.67x10-8 W/m 2 K 4. The total power emitted by a blackbody with surface area A and surface temperature T is then P total =! e A T 4 The wavelength! max at which the emitted intensity has a maximum value is related to the absolute temperature T on the surface of the object according to Wien s displacement law: # "3 T = 2.898x m! K max 10 20
21 B. Planck s hypothesis Any physical entity with one degree of freedom whose coordinates execute simple harmonic oscillations can possess only total energies! which satisfy the relation! = n h f Where f is the frequency of oscillation and h is a universal constant known as Planck s constant. The value of Planck s constant is 6.63x10-34 J s. The energy! of an entity obeying Planck s postulate is said to be quantized, the allowed states are called quantum states, and the integer n is called a quantum number. Since n is an integer, that is, n = 0, 1, 2, 3, 4, then it follows that the allowed values of the total energy! are! = 0, h f, 2 h f, 3h f, 4 h f,... For his theoretical analysis of blackbody radiation, Max Planck was awarded the Nobel Prize in Physics in
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 informationPlanck 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 informationEnergy 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 informationChapter 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 informationChapter 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 informationChapter 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 informationis 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 informationGeneral Physics (PHY 2140)
General Physics (PHY 140) Lecture 33 Modern Physics Atomic Physics Atomic spectra Bohr s theory of hydrogen http://www.physics.wayne.edu/~apetrov/phy140/ Chapter 8 1 Lightning Review Last lecture: 1. Atomic
More informationParticle 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 informationUNIT : QUANTUM THEORY AND THE ATOM
Name St.No. Date(YY/MM/DD) / / Section UNIT 102-10: QUANTUM THEORY AND THE ATOM OBJECTIVES Atomic Spectra for Hydrogen, Mercury and Neon. 1. To observe various atomic spectra with a diffraction grating
More informationChapter 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 informationPreview. 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 informationChapter 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 information1) Introduction 2) Photo electric effect 3) Dual nature of matter 4) Bohr s atom model 5) LASERS
1) Introduction 2) Photo electric effect 3) Dual nature of matter 4) Bohr s atom model 5) LASERS 1. Introduction Types of electron emission, Dunnington s method, different types of spectra, Fraunhoffer
More informationThe 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 informationChapters 31 Atomic Physics
Chapters 31 Atomic Physics 1 Overview of Chapter 31 Early Models of the Atom The Spectrum of Atomic Hydrogen Bohr s Model of the Hydrogen Atom de Broglie Waves and the Bohr Model The Quantum Mechanical
More information2.1- CLASSICAL CONCEPTS; Dr. A. DAYALAN, Former Prof & Head 1
2.1- CLASSICAL CONCEPTS; Dr. A. DAYALAN, Former Prof & Head 1 QC-2 QUANTUM CHEMISTRY (Classical Concept) Dr. A. DAYALAN,Former Professor & Head, Dept. of Chemistry, LOYOLA COLLEGE (Autonomous), Chennai
More informationTHE UNIVERSITY OF QUEENSLAND DEPARTMENT OF PHYSICS PHYS2041 ATOMIC SPECTROSCOPY
THE UNIVERSITY OF QUEENSLAND DEPARTMENT OF PHYSICS PHYS2041 ATOMIC SPECTROSCOPY Warning: The mercury spectral lamps emit UV radiation. Do not stare into the lamp. Avoid exposure where possible. Introduction
More informationChapter 31 Atomic Physics
100 92 86 100 92 84 100 92 84 98 92 83 97 92 82 96 91 80 96 91 76 95 91 74 95 90 68 95 89 67 95 89 66 94 87 93 86 No. of Students in Range Exam 3 Score Distribution 25 22 20 15 10 10 5 3 2 0 0 0 0 0 0
More informationAtomic Structure and the Periodic Table
Atomic Structure and the Periodic Table The electronic structure of an atom determines its characteristics Studying atoms by analyzing light emissions/absorptions Spectroscopy: analysis of light emitted
More informationSemiconductor 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 informationSCH4U: History of the Quantum Theory
SCH4U: History of the Quantum Theory Black Body Radiation When an object is heated, it initially glows red hot and at higher temperatures becomes white hot. This white light must consist of all of the
More informationChapter 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 informationPhysics 1C Lecture 29B
Physics 1C Lecture 29B Emission Spectra! The easiest gas to analyze is hydrogen gas.! Four prominent visible lines were observed, as well as several ultraviolet lines.! In 1885, Johann Balmer, found a
More informationCh 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 informationChapter 29 Atomic Physics. Looking Ahead. Slide 29-1
Chapter 29 Atomic Physics Looking Ahead Slide 29-1 Atomic Spectra and the Bohr Model In the mid 1800s it became apparent that the spectra of atomic gases is comprised of individual emission lines. Slide
More informationChapter 27 Early Quantum Theory and Models of the Atom
Chapter 27 Early Quantum Theory and Models of the Atom Modern Physics 19th century physics had so many great successes, that most people felt nature was almost fully understood. Just a few small clouds
More informationwhere n = (an integer) =
5.111 Lecture Summary #5 Readings for today: Section 1.3 (1.6 in 3 rd ed) Atomic Spectra, Section 1.7 up to equation 9b (1.5 up to eq. 8b in 3 rd ed) Wavefunctions and Energy Levels, Section 1.8 (1.7 in
More informationPhysics 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 informationGeneral Physics (PHY 2140)
General Physics (PHY 2140) Lecture 27 Modern Physics Quantum Physics Blackbody radiation Plank s hypothesis http://www.physics.wayne.edu/~apetrov/phy2140/ Chapter 27 1 Quantum Physics 2 Introduction: Need
More informationTHE 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 informationEarly 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 informationLecture 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 informationOutline Chapter 9 The Atom Photons Photons The Photoelectron Effect Photons Photons
Outline Chapter 9 The Atom 9-1. Photoelectric Effect 9-3. What Is Light? 9-4. X-rays 9-5. De Broglie Waves 9-6. Waves of What? 9-7. Uncertainty Principle 9-8. Atomic Spectra 9-9. The Bohr Model 9-10. Electron
More informationChapter 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 informationPhysical 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 informationAccounts 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 informationThe 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 informationSharif University of Technology Physics Department. Modern Physics Spring 2016 Prof. Akhavan
Sharif University of Technology Physics Department Modern Physics Spring 2016 Prof. Akhavan Problems Set #5. Due on: 03 th of April / 15 th of Farvardin. 1 Blackbody Radiation. (Required text book is Modern
More informationProblems with the atomic model?
Modern Atomic Theory- Electronic Structure of Atoms DR HNIMIR-CH7 Where should (-) electrons be found? Problems with the atomic model? First, a Little About Electromagnetic Radiation- Waves Another Look
More informationAtomic 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 informationPhysics 102: Lecture 24. Bohr vs. Correct Model of Atom. Physics 102: Lecture 24, Slide 1
Physics 102: Lecture 24 Bohr vs. Correct Model of Atom Physics 102: Lecture 24, Slide 1 Plum Pudding Early Model for Atom positive and negative charges uniformly distributed throughout the atom like plums
More informationChapter 28 Quantum Mechanics of Atoms
Chapter 28 Quantum Mechanics of Atoms 28.1 Quantum Mechanics The Theory Quantum mechanics incorporates wave-particle duality, and successfully explains energy states in complex atoms and molecules, the
More informationSpectroscopy. Hot self-luminous objects light the Sun or a light bulb emit a continuous spectrum of wavelengths.
Hot self-luminous objects light the Sun or a light bulb emit a continuous spectrum of wavelengths. In contract, light emitted in low=pressure gas discharge contains only discrete individual wavelengths,
More informationStellar 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 informationNicholas J. Giordano. Chapter 29. Atomic Theory. Marilyn Akins, PhD Broome Community College
Nicholas J. Giordano www.cengage.com/physics/giordano Chapter 29 Atomic Theory Marilyn Akins, PhD Broome Community College Atomic Theory Matter is composed of atoms Atoms are assembled from electrons,
More informationOpenStax-CNX module: m The Bohr Model. OpenStax College. Abstract
OpenStax-CNX module: m51039 1 The Bohr Model OpenStax College This work is produced by OpenStax-CNX and licensed under the Creative Commons Attribution License 4.0 By the end of this section, you will
More informationChapter 27. Quantum Physics
Chapter 27 Quantum Physics Need for Quantum Physics Problems remained from classical mechanics that relativity didn t explain Blackbody Radiation The electromagnetic radiation emitted by a heated object
More informationModels 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 information298 Chapter 6 Electronic Structure and Periodic Properties of Elements
98 Chapter 6 Electronic Structure and Periodic Properties of Elements 6. The Bohr Model By the end of this section, you will be able to: Describe the Bohr model of the hydrogen atom Use the Rydberg equation
More informationPHYS 172: Modern Mechanics Fall 2009
PHYS 172: Modern Mechanics Fall 2009 Lecture 14 Energy Quantization Read 7.1 7.9 Reading Question: Ch. 7, Secs 1-5 A simple model for the hydrogen atom treats the electron as a particle in circular orbit
More informationCHEMISTRY 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 informationPhysics 116. Nov 22, Session 32 Models of atoms. R. J. Wilkes
Physics 116 Session 32 Models of atoms Nov 22, 2011 Thomson Rutherford R. J. Wilkes Email: ph116@u.washington.edu Announcements Exam 3 next week (Tuesday, 11/29) Usual format and procedures I ll post example
More information4/14/2015. 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 informationFrom Last Time. Electron diffraction. Making a particle out of waves. Planetary model of atom. Using quantum mechanics ev 1/ 2 nm E kinetic
From Last Time All objects show both wave-like properties and particle-like properties. Electromagnetic radiation (e.g. light) shows interference effects (wave-like properties), but also comes in discrete
More informationChapter 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 informationAstro 210 Lecture 13 Feb 16, 2011
Astro 210 Lecture 13 Feb 16, 2011 Announcements Hour Exam 1 in class Friday info online HW1 bonus problem due online Friday last Planetarium shows: tomorrow and Monday registration, report forms, info
More informationChapter 5 Light and Matter
Chapter 5 Light and Matter Stars and galaxies are too far for us to send a spacecraft or to visit (in our lifetimes). All we can receive from them is light But there is much we can learn (composition,
More informationQuestion 12.1: Choose the correct alternative from the clues given at the end of the each statement: (a) The size of the atom in Thomson s model is... the atomic size in Rutherford s model. (much greater
More informationAtomic Structure 11/21/2011
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 informationExam 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 informationChapter 22 Quantum Mechanics & Atomic Structure 22.1 Photon Theory of Light and The Photoelectric Effect Homework # 170
22.1 Photon Theory of Light and The Photoelectric Effect Homework # 170 See Homework #95 in "Chapter 12-Electrostatics" for the table of "Useful nformation" on atomic particles. 01. What is the energy
More informationBlackbody radiation The photoelectric effect Compton effect Line spectra Nuclear physics/bohr model Lasers Quantum mechanics
Blackbody radiation The photoelectric effect Compton effect Line spectra Nuclear physics/bohr model Lasers Quantum mechanics Phys 2435: Chap. 38, Pg 1 Blackbody radiation New Topic Phys 2435: Chap. 38,
More informationLECTURE 23 SPECTROSCOPY AND ATOMIC MODELS. Instructor: Kazumi Tolich
LECTURE 23 SPECTROSCOPY AND ATOMIC MODELS Instructor: Kazumi Tolich Lecture 23 2 29.1 Spectroscopy 29.2 Atoms The first nuclear physics experiment Using the nuclear model 29.3 Bohr s model of atomic quantization
More informationLECTURE # 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 informationModern 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 informationAstronomy 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 informationQuantum theory and models of the atom
Guess now. It has been found experimentally that: (a) light behaves as a wave; (b) light behaves as a particle; (c) electrons behave as particles; (d) electrons behave as waves; (e) all of the above are
More informationChapter 7 QUANTUM THEORY & ATOMIC STRUCTURE Brooks/Cole - Thomson
Chapter 7 QUANTUM THEORY & ATOMIC STRUCTURE 1 7.1 The Nature of Light 2 Most subatomic particles behave as PARTICLES and obey the physics of waves. Light is a type of electromagnetic radiation Light consists
More information12/04/2012. 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 information8 Wavefunctions - Schrödinger s Equation
8 Wavefunctions - Schrödinger s Equation So far we have considered only free particles - i.e. particles whose energy consists entirely of its kinetic energy. In general, however, a particle moves under
More informationCHAPTER 28 Quantum Mechanics of Atoms Units
CHAPTER 28 Quantum Mechanics of Atoms Units Quantum Mechanics A New Theory The Wave Function and Its Interpretation; the Double-Slit Experiment The Heisenberg Uncertainty Principle Philosophic Implications;
More informationQuantum 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 informationParticle Detectors and Quantum Physics (2) Stefan Westerhoff Columbia University NYSPT Summer Institute 2002
Particle Detectors and Quantum Physics (2) Stefan Westerhoff Columbia University NYSPT Summer Institute 2002 More Quantum Physics We know now how to detect light (or photons) One possibility to detect
More informationModern Physics- Introduction. L 35 Modern Physics [1] ATOMS and classical physics. Newton s Laws have flaws! accelerated charges radiate energy
L 35 Modern Physics [1] Introduction- quantum physics Particles of light PHOTONS The photoelectric effect Photocells & intrusion detection devices The Bohr atom emission & absorption of radiation LASERS
More informationAn electron can be liberated from a surface due to particle collisions an electron and a photon.
Quantum Theory and the Atom the Bohr Atom The story so far... 1. Einstein argued that light is a photon (particle) and each photon has a discrete amount of energy associated with it governed by Planck's
More informationMystery #3 Emission Spectra of Elements. Tube filled with elemental gas. Voltage can be applied across both ends, this causes the gas to emit light
Mystery #3 Emission Spectra of Elements Tube filled with elemental gas. Voltage can be applied across both ends, this causes the gas to emit light Line Spectra Copyright The McGraw-Hill Companies, Inc.
More informationChapter 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 informationModule 02: Wave-particle duality, de Broglie waves and the Uncertainty principle
PG Pathshala Subject: BIOPHYSICS Paper 0: Quantum Biophysics Module 0: Wave-particle duality, de Broglie waves and the Uncertainty principle Principal Investigator: Prof. Moganty R. Rajeswari Professor,
More informationComplete nomenclature for electron orbitals
Complete nomenclature for electron orbitals Bohr s model worked but it lacked a satisfactory reason why. De Broglie suggested that all particles have a wave nature. u l=h/p Enter de Broglie again It was
More informationLecture 11: The Bohr Model. PHYS 2130: Modern Physics Prof. Ethan Neil
Lecture 11: The Bohr Model PHYS 2130: Modern Physics Prof. Ethan Neil (ethan.neil@colorado.edu) Announcements/reminders Midterm Exam #1 next Thursday at 7:30 PM HALE 270 (see class website for details)
More informationChapter 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 informationElectronic 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 information38 The Atom and the Quantum. Material particles and light have both wave properties and particle properties.
Material particles and light have both wave properties and particle properties. 38 The Atom and the Quantum Atomic structure is revealed by analyzing light. Light has a dual nature, which in turn radically
More informationMaterial particles and light have both wave properties and particle properties Models
Material particles and light have both wave properties and particle properties. Atomic structure is revealed by analyzing light. Light has a dual nature, which in turn radically alters our understanding
More information29:006 FINAL EXAM FRIDAY MAY 11 3:00 5:00 PM IN LR1 VAN
L 33 Modern Physics [1] 29:006 FINAL EXAM FRIDAY MAY 11 3:00 5:00 PM IN LR1 VAN Introduction- quantum physics Particles of light PHOTONS The photoelectric effect Photocells & intrusion detection devices
More informationChapter 6: The Electronic Structure of the Atom Electromagnetic Spectrum. All EM radiation travels at the speed of light, c = 3 x 10 8 m/s
Chapter 6: The Electronic Structure of the Atom Electromagnetic Spectrum V I B G Y O R All EM radiation travels at the speed of light, c = 3 x 10 8 m/s Electromagnetic radiation is a wave with a wavelength
More informationEarly 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 informationATOMIC MODELS. Models are formulated to fit the available data. Atom was known to have certain size. Atom was known to be neutral.
ATOMIC MODELS Models are formulated to fit the available data. 1900 Atom was known to have certain size. Atom was known to be neutral. Atom was known to give off electrons. THOMPSON MODEL To satisfy the
More information1/l = R(1/n' 2-1/n 2 ) n > n', both integers R = nm -1
Worksheet 14 Bohr Model of the Hydrogen Atom In the late 1800's, Johannes Rydberg, building on the work of Johann Balmer, had come up with a mathematical formula that could be used to find the wavelengths
More informationWAVE 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 informationWe 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 informationEarlier we learned that hot, opaque objects produce continuous spectra of radiation of different wavelengths.
Section7: The Bohr Atom Earlier we learned that hot, opaque objects produce continuous spectra of radiation of different wavelengths. Continuous Spectrum Everyone has seen the spectrum produced when white
More informationChapter 4 Electron Configurations
Chapter 4 Electron Configurations Waves Today scientists recognize light has properties of waves and particles Waves: light is electromagnetic radiation and travels in electromagnetic waves. 4 Characteristics
More informationChapter 28 Assignment Solutions
Chapter 28 Assignment Solutions Page 770 #23-26, 29-30, 43-48, 55 23) Complete the following concept map using these terms: energy levels, fixed electron radii, Bohr model, photon emission and absorption,
More informationChemistry 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 informationThe following experimental observations (between 1895 and 1911) needed new quantum ideas:
The following experimental observations (between 1895 and 1911) needed new quantum ideas: 1. Spectrum of Black Body Radiation: Thermal Radiation 2. The photo electric effect: Emission of electrons from
More informationX-Rays from Atoms. These are called K α X-rays See table 29.1 for the energy of K α X-rays produced by some elements. Section 29.3
X-Rays from Atoms The highest photon energy available in a hydrogen atom is in the ultraviolet part of the electromagnetic spectrum Other atoms can emit much more energetic photons larger Z, more electric
More informationChapter 1 The Bohr Atom
Chapter 1 The Bohr Atom 1 Introduction Niels Bohr was a Danish physicist who made a fundamental contribution to our understanding of atomic structure and quantum mechanics. He made the first successful
More informationProperties of Light and Atomic Structure. Chapter 7. So Where are the Electrons? Electronic Structure of Atoms. The Wave Nature of Light!
Properties of Light and Atomic Structure Chapter 7 So Where are the Electrons? We know where the protons and neutrons are Nuclear structure of atoms (Chapter 2) The interaction of light and matter helps
More information