CHAPTER 2: POSTULATES OF QUANTUM MECHANICS

Size: px
Start display at page:

Download "CHAPTER 2: POSTULATES OF QUANTUM MECHANICS"

Transcription

1 CHAPTER 2: POSTULATES OF QUANTUM MECHANICS

2 Basics of Quantum Mechanics - Why Quantum Physics? - Classical mechanics (Newton's mechanics) and Maxwell's equations (electromagnetics theory) can explain MACROSCOPIC phenomena such as motion of billiard balls or rockets. Quantum mechanics is used to explain microscopic phenomena such as photon-atom scattering and flow of the electrons in a semiconductor. QUANTUM MECHANICS is a collection of postulates based on a huge number of experimental observations. The differences between the classical and quantum mechanics can be understood by examining both The classical point of view The quantum point of view

3 Basics of Quantum Mechanics - Classical Point of View - In Newtonian mechanics, the laws are written in terms of PARTICLE TRAJECTORIES. A PARTICLE is an indivisible mass point object that has a variety of properties that can be measured, which we call observables. The observables specify the state of the particle (position and momentum). A SYSTEM is a collection of particles, which interact among themselves via internal forces, and can also interact with the outside world via external forces. The STATE OF A SYSTEM is a collection of the states of the particles that comprise the system. All properties of a particle can be known to infinite precision. Conclusions: TRAJECTORY state descriptor of Newtonian physics, EVOLUTION OF THE STATE Use Newton's second law PRINCIPLE OF CAUSALITY Two identical systems with the same initial conditions, subject to the same measurement will yield the same result.

4 Basics of Quantum Mechanics - Quantum Point of View - Quantum particles can act as both particles and waves WAVE-PARTICLE DUALITY. Quantum state is a conglomeration of several possible outcomes of measurement of physical properties Quantum mechanics uses the language of PROBABILITY theory (random chance). An observer cannot observe a microscopic system without altering some of its properties. Neither one can predict how the state of the system will change. QUANTIZATION of energy is yet another property of "microscopic" particles.

5 Basics of Quantum Mechanics - Heisenberg Uncertainty Principle - One cannot unambiguously specify the values of particle's position and its momentum for a microscopic particle, i.e (H.U.P): x ( t 1 0 ) p ( 0) h x t 2 2 Position and momentum are, therefore, considered as incompatible variables. The Heisenberg Uncertainty Principle (H.U.P) strikes at the very heart of the classical physics => the particle trajectory.

6 Basics of Quantum Mechanics - The Correspondence Principle - When Quantum physics is applied to macroscopic systems, it must reduce to the classical physics. Therefore, the nonclassical phenomena, such as uncertainty and duality, must become undetectable. Niels Bohr codified this requirement into his Correspondence principle:

7 Basics of Quantum Mechanics - Particle-Wave Duality - The behavior of a "microscopic" particle is very different from that of a classical particle: in some experiments it resembles the behavior of a classical wave (not localized in space), in other experiments it behaves as a classical particle (localized in space). Corpuscular theories of light treat light as though it were composed of particles, but can not explain DIFRACTION and INTERFERENCE. Maxwell's theory of electromagnetic radiation can explain these two phenomena, which was the reason why the corpuscular theory of light was abandoned.

8 Basics of Quantum Mechanics - Particle-Wave Duality - Waves as particles: Max Plank work on black-body radiation, in which he assumed that the molecules of the cavity walls, described using a simple oscillator model, can only exchange energy in quantized units Einstein proposed that the energy in an electromagnetic field is not spread out over a spherical wavefront, but instead is localized in individual clumbs - quanta. Each quantum of frequency n travels through space with speed of light, carrying a discrete amount of energy and momentum =photon => used to explain the photoelectric effect, later to be confirmed by the x-ray experiments of Compton. Particles as waves Double-slit experiment, in which instead of using a light source, one uses the electron gun. The electrons are diffracted by the slit and then interfere in the region between the diaphragm and the detector. Aharonov-Bohm effect

9 Planck s constant in action The classical picture began to crumble in 1900 when Max Planck published a theory of black-body radiation (theory of thermal radiation in equilibrium with a perfectly absorbing body). Planck provided an explanation of the observed properties of black-body radiation by assuming that atoms emit and absorb DISCRETE quanta of the radiation with energy E = hv, where v freq. of the radiation and h is the fundamental constant of nature with value: h = x J.s => Planck s constant

10 Recall: Photons PHOTONS - light particle. - particle-like quanta of EM radiation. - travel at speed of light c with momentum p and energy E, given by: p=h/ and E = hc/ For visible photon with wavelength = 663 nm; => p = Js and E = 3 x J # 1ev = x J ; x-ray photons ~ 10 kev. Evidence become compelling when A.H. Compton s experiment, later called Compton scattering.

11 Recall: Atoms It s well known that atoms can exist in states with DISCRETE of QUANTIZED energy. For example, the energy levels for H atom, consisting of an electron and a proton, where a good approx. the bound states have quantized energies given by E n = -13.6/n 2 ev, n the principle quantum number, n = 1,2,3, When the excitation energy > 13.6 ev, the atom is ionized (e is no longer bound to the proton) and its energy can, in principle, take on any value in the continuum between E = 0 and E =. The ground state, E g or 0> of H has n = 1, and the 1 st excitation state has n = 2 and so on.

12 Recall: Atoms Transition between hydrogen-atoms states with n i and n f leads to a spectral line (in EM spectra) with a wavelength given by hc/ = E ni E nf Atoms => Bohr atomic model => Bohr atomic radius, i.e., H atom, a 0 = x m. => Rydberg energy, i.e., H atom, E R = 13.6 ev. => Pauli Exclusion Principle => Heisenberg Uncertainty Principle (measurement) => Postulates of Quantum Mechanics (measurement)

13 POSTULATES OF QUANTUM MECHANICS Postulate: A fundamental element; a basic principle.

14 Postulates of Quantum Mechanics The foundation of Quantum Mechanics (QM) are the postulates, and the applications of QM are built on this foundation. Briefly, the postulates are: Postulate #1 (the wave function); State of a System Postulate #2 (Operators); Observables & Operators Postulate #3 (Measurements); Measurements & Eigenvalues of Operators Postulate #4 (Expectation values); Probabilistic outcome of measurements Postulate #5 (Time dependence) Time evolution of a system QM: Concepts & Applications, Nouredine Zettili.

15 The Postulates of Quantum Mechanics POSTULATES Definition #1 The wavefunction attempts to describe a quantum mechanical entity (photon, electron, x-ray, etc.) through its spatial location and time dependence, i.e. the wavefunction is in the most general sense dependent on time and space; = (x, t). #2 For every measurable property of the system in classical mechanics such as position, momentum, and energy, there exists a corresponding operator in quantum mechanics. An experiment in the lab to measure a value for such an observable is simulated in theory by operating on the wavefunction of the system with the corresponding operator. #3 For a single measurement of an observable corresponding to a quantum mechanical operator, only values that are eigenvalues of the operator will be measured. #4 The average, or expectation, value of an observable corresponding to a quantum mechanical operator (A) is given by: #5 The time-dependent Schrodinger equation governs the time evolution of a quantum mechanical system: x t Hˆ (, ) ( x, t) i t a *( x, t) Aˆ ( x, t) dx *( x, t) ( x, t) dx

16 Basics of Quantum Mechanics - What is Quantum Mechanics? - Quantum Mechanics is nothing more but linear algebra and Hilbert spaces. What makes quantum mechanics quantum mechanics is the physical interpretation of the results that are obtained.

17 Basics of Quantum Mechanics - First Postulate of Quantum Mechanics - The wavefunction attempts to describe a quantum mechanical entity (photon, electron, x-ray, etc.) through its spatial location and time dependence, i.e. the wavefunction is in the most general sense dependent on time and space; = (x, t) The state of a quantum mechanical system is completely specified by the wavefunction (x, t). First postulate of Quantum mechanics: Every physically-realizable state of the system is described in quantum mechanics by a state function that contains all accessible physical information about the system in that state. Physically realizable states states that can be studied in laboratory Accesible information the information we can extract from the wavefunction State function function of position, momentum, energy that is spatially localized.

18 Basics of Quantum Mechanics - First Postulate of Quantum Mechanics - If 1 and 2 represent two physically-realizable states of the system, then the linear combination c 11 c22 where c 1 and c 2 are arbitrary complex constants, represents a third physically realizable state of the system. Note: Wavefunction (x,t) position and time probability amplitude Quantum mechanics describes the outcome of an ensemble of measurements, where an ensemble of measurements consists of a very large number of identical experiments performed on identical non-interacting systems, all of which have been identically prepared so as to be in the same state.

19 First Postulate of Quantum Mechanics

20 First Postulate of Quantum Mechanics PdV ( x, y, z) 2 dv * ( x, y, z) ( x, y, z) dv 1 Limitations on the wavefunction: Only normalizable functions can represent a quantum state and these are called physically admissible functions. State function must be continuous and single valued function. State function must be a smoothly-varying function (continuous derivative).

21 First Postulate of Quantum Mechanics

22 Basics of Quantum Mechanics - Second Postulate of Quantum Mechanics - A The line segments AB and CD are orthogonal to each other. C B D

23 Second Postulate of Quantum Mechanics List of classical observables and QM operator

24 Basics of Quantum Mechanics - Third Postulate of Quantum Mechanics - Third Postulate:

25 Forth Postulate of Quantum Mechanics

26 Forth Postulate of Quantum Mechanics

27 Forth Postulate of Quantum Mechanics

28 Forth Postulate of Quantum Mechanics

29 Forth Postulate of Quantum Mechanics

30 Fifth Postulate of Quantum Mechanics

31 Fifth Postulate of Quantum Mechanics

32 Fifth Postulate of Quantum Mechanics

33 Postulates of Quantum Mechanics

34 Postulates of Quantum Mechanics EXAMPLE: Which among the following functions represent physically acceptable wave functions: 2 2 ) ( ; 5 ) ( ; 4 ) ( ; 3sin ) ( x x e x x h x x g x x f

35 Postulates of Quantum Mechanics

36 Postulates of Quantum Mechanics Orthonormal: Two vectors are orthonormal if: 1. Their dot product is zero. 2. The two vectors are unit vectors. j 0 90 i i j i j 0 1

37 Postulates of Quantum Mechanics EXAMPLE:

38 Postulates of Quantum Mechanics

39 Postulates of Quantum Mechanics

40 Postulates of Quantum Mechanics

41 Observable & Operators An observable is a dynamical variable that can be measured; the dynamical variables encountered most in classical mechanics are the position, linear momentum, angular momentum, and energy. How do we mathematically represent these and other variables in Quantum Mechanics?

42 Observable & Operators

43 Observable & Operators

44 Observable & Operators

45 Observable & Operators Formulate the operator representing the classical orbital angular momentum.

46 Measurement in Quantum Mechanics Quantum theory is about the results of measurement; it says nothing about what might happen in the physical world outside the context of measurement. So, the emphasis is on measurement.

47 Measurement in Quantum Mechanics How measurements disturb systems?

48 Measurement in Quantum Mechanics

49 Measurement in Quantum Mechanics

50 Measurement in Quantum Mechanics Expectation Values

51 Measurement in Quantum Mechanics

52 Measurement in Quantum Mechanics EXAMPLE:

53 Measurement in Quantum Mechanics

54 Measurement in Quantum Mechanics

55 Measurement in Quantum Mechanics

Quantum Mechanics. Semester /2015. (Introduction)

Quantum Mechanics. Semester /2015. (Introduction) EMT 295/3 Quantum Mechanics Semester 1 2014/2015 (Introduction) EMT 295 Course Outcomes (COs): CO1: Ability to explain the concept and principles of modern physics, quantization and postulates of quantum

More information

Electronic Structure of Atoms. Chapter 6

Electronic Structure of Atoms. Chapter 6 Electronic Structure of Atoms Chapter 6 Electronic Structure of Atoms 1. The Wave Nature of Light All waves have: a) characteristic wavelength, λ b) amplitude, A Electronic Structure of Atoms 1. The Wave

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

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

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

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

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

Quantum Theory and Atomic Structure. Quantum Mechanics. Quantum Theory and Atomic Structure. 7.3 The Wave-Particle Duality of Matter and Energy

Quantum Theory and Atomic Structure. Quantum Mechanics. Quantum Theory and Atomic Structure. 7.3 The Wave-Particle Duality of Matter and Energy Chapter 7 Quantum Theory and Atomic Structure Chap 7-1 Quantum Theory and Atomic Structure 7.1 The Nature of Light 7.2 Atomic Spectra 7.3 The Wave-Particle Duality of Matter and Energy 7.4 The Quantum-Mechanical

More information

Chapter 7. Quantum Theory and Atomic Structure. Quantum Mechanics. Chap 7-1

Chapter 7. Quantum Theory and Atomic Structure. Quantum Mechanics. Chap 7-1 Chapter 7 Quantum Theory and Atomic Structure Chap 7-1 Quantum Theory and Atomic Structure 7.1 The Nature of Light 7.2 Atomic Spectra 7.3 The Wave-Particle Duality of Matter and Energy 7.4 The Quantum-Mechanical

More information

10/17/11. Chapter 7. Quantum Theory and Atomic Structure. Amplitude (intensity) of a wave. Quantum Theory and Atomic Structure

10/17/11. Chapter 7. Quantum Theory and Atomic Structure. Amplitude (intensity) of a wave. Quantum Theory and Atomic Structure Quantum Theory and Atomic Structure Chapter 7 7. The Nature of Light Quantum Theory and Atomic Structure 7. Atomic Spectra 7. The Wave-Particle Duality of Matter and Energy 7.4 The Quantum-Mechanical Model

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

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

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

Chapter 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. 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 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

CHAPTER I Review of Modern Physics. A. Review of Important Experiments

CHAPTER I Review of Modern Physics. A. Review of Important Experiments CHAPTER I Review of Modern Physics A. Review of Important Experiments Quantum Mechanics is analogous to Newtonian Mechanics in that it is basically a system of rules which describe what happens at the

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

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

Atomic Structure and the Periodic Table

Atomic 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 information

Theoretical Biophysics. Quantum Theory and Molecular Dynamics. Pawel Romanczuk WS 2017/18

Theoretical Biophysics. Quantum Theory and Molecular Dynamics. Pawel Romanczuk WS 2017/18 Theoretical Biophysics Quantum Theory and Molecular Dynamics Pawel Romanczuk WS 2017/18 http://lab.romanczuk.de/teaching/ 1 Introduction Two pillars of classical theoretical physics at the begin of 20th

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

CHAPTER 28 Quantum Mechanics of Atoms Units

CHAPTER 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 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

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

APPLIED OPTICS. Lecture-1: EVOLUTION of our UNDERSTANDING of LIGHT. Is it a stream of particles?

APPLIED OPTICS. Lecture-1: EVOLUTION of our UNDERSTANDING of LIGHT. Is it a stream of particles? A. La Rosa Lecture Notes APPLIED OPTICS Lecture-1: EVOLUTION of our UNDERSTANDING of LIGHT What is light? Is it a wave? Is it a stream of particles? A. Light as a particle NEWTON (164 177) was the most

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

Particles and Waves Particles Waves

Particles and Waves Particles Waves Particles and Waves Particles Discrete and occupy space Exist in only one location at a time Position and velocity can be determined with infinite accuracy Interact by collisions, scattering. Waves Extended,

More information

Quantum physics (quantum theory, quantum mechanics) Part 1

Quantum physics (quantum theory, quantum mechanics) Part 1 Quantum physics (quantum theory, quantum mechanics) Part 1 1 Outline Introduction Problems of classical physics Black-body Radiation experimental observations Wien s displacement law Stefan Boltzmann law

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

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

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

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

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

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

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

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

Quantum Mechanics of Atoms

Quantum Mechanics of Atoms Quantum Mechanics of Atoms Your theory is crazy, but it's not crazy enough to be true N. Bohr to W. Pauli Quantum Mechanics of Atoms 2 Limitations of the Bohr Model The model was a great break-through,

More information

Conceptual Physics Fundamentals

Conceptual Physics Fundamentals Conceptual Physics Fundamentals Chapter 15: QUANTUM THEORY This lecture will help you understand: The Photoelectric Effect Absorption Spectra Fluorescence Incandescence Lasers Wave-Particle Duality Particles

More information

SCH4U: History of the Quantum Theory

SCH4U: 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 information

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

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

Wave function and Quantum Physics

Wave function and Quantum Physics Wave function and Quantum Physics Properties of matter Consists of discreet particles Atoms, Molecules etc. Matter has momentum (mass) A well defined trajectory Does not diffract or interfere 1 particle

More information

DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS

DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS LSN 12-1A: INTERACTIONS OF MATTER WITH RADIATION Questions From Reading Activity? Essential Idea: The microscopic quantum world offers a range of phenomena,

More information

Light was recognised as a wave phenomenon well before its electromagnetic character became known.

Light was recognised as a wave phenomenon well before its electromagnetic character became known. VISUAL PHYSICS ONLINE MODULE 7 NATURE OF LIGHT WAVE or PARTICLE??? Light was recognised as a wave phenomenon well before its electromagnetic character became known. The problem of the nature of light is

More information

Electromagnetic Radiation. Chapter 12: Phenomena. Chapter 12: Quantum Mechanics and Atomic Theory. Quantum Theory. Electromagnetic Radiation

Electromagnetic Radiation. Chapter 12: Phenomena. Chapter 12: Quantum Mechanics and Atomic Theory. Quantum Theory. Electromagnetic Radiation Chapter 12: Phenomena Phenomena: Different wavelengths of electromagnetic radiation were directed onto two different metal sample (see picture). Scientists then recorded if any particles were ejected and

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

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

Explain how Planck resolved the ultraviolet catastrophe in blackbody radiation. Calculate energy of quanta using Planck s equation.

Explain how Planck resolved the ultraviolet catastrophe in blackbody radiation. Calculate energy of quanta using Planck s equation. Objectives Explain how Planck resolved the ultraviolet catastrophe in blackbody radiation. Calculate energy of quanta using Planck s equation. Solve problems involving maximum kinetic energy, work function,

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

The Electron Cloud. Here is what we know about the electron cloud:

The Electron Cloud. Here is what we know about the electron cloud: The Electron Cloud Here is what we know about the electron cloud: It contains the subatomic particles called electrons This area accounts for most of the volume of the atom ( empty space) These electrons

More information

Rapid Review of Early Quantum Mechanics

Rapid Review of Early Quantum Mechanics Rapid Review of Early Quantum Mechanics 8/9/07 (Note: This is stuff you already know from an undergraduate Modern Physics course. We re going through it quickly just to remind you: more details are to

More information

CHAPTER 5 Wave Properties of Matter and Quantum Mechanics I

CHAPTER 5 Wave Properties of Matter and Quantum Mechanics I CHAPTER 5 Wave Properties of Matter and Quantum Mechanics I 5.1 X-Ray Scattering 5. De Broglie Waves 5.3 Electron Scattering 5.4 Wave Motion 5.5 Waves or Particles? 5.6 Uncertainty Principle Many experimental

More information

Chapter 12: Phenomena

Chapter 12: Phenomena Chapter 12: Phenomena K Fe Phenomena: Different wavelengths of electromagnetic radiation were directed onto two different metal sample (see picture). Scientists then recorded if any particles were ejected

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

Class 21. Early Quantum Mechanics and the Wave Nature of Matter. Physics 106. Winter Press CTRL-L to view as a slide show. Class 21.

Class 21. Early Quantum Mechanics and the Wave Nature of Matter. Physics 106. Winter Press CTRL-L to view as a slide show. Class 21. Early and the Wave Nature of Matter Winter 2018 Press CTRL-L to view as a slide show. Last Time Last time we discussed: Optical systems Midterm 2 Today we will discuss: Quick of X-ray diffraction Compton

More information

8 Wavefunctions - Schrödinger s Equation

8 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 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

QUANTUM THEORY & ATOMIC STRUCTURE

QUANTUM THEORY & ATOMIC STRUCTURE QUANTUM THEORY & ATOMIC STRUCTURE GENERAL CHEMISTRY by Dr. Istadi 1 THE NATURE OF LIGHT Visible light is one type of electromagnetic radiation ( radiation (electromagnetic The electromagnetic radiation

More information

Chapter 6. Electronic Structure of Atoms. Lecture Presentation. John D. Bookstaver St. Charles Community College Cottleville, MO

Chapter 6. Electronic Structure of Atoms. Lecture Presentation. John D. Bookstaver St. Charles Community College Cottleville, MO Lecture Presentation Chapter 6 John D. Bookstaver St. Charles Community College Cottleville, MO Waves To understand the electronic structure of atoms, one must understand the nature of electromagnetic

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

Radiation and the Atom

Radiation and the Atom Radiation and the Atom PHYS Lecture Departamento de Física Instituto Superior de Engenharia do Porto cav@isep.ipp.pt Overview SI Units and Prefixes Radiation Electromagnetic Radiation Electromagnetic Spectrum

More information

Chapter 7 QUANTUM THEORY & ATOMIC STRUCTURE Brooks/Cole - Thomson

Chapter 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 information

Lecture Outline Chapter 30. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc.

Lecture Outline Chapter 30. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc. Lecture Outline Chapter 30 Physics, 4 th Edition James S. Walker Chapter 30 Quantum Physics Units of Chapter 30 Blackbody Radiation and Planck s Hypothesis of Quantized Energy Photons and the Photoelectric

More information

WAVE-PARTICLE DUALITY. Katrina Forrestall & Emily Kingsbury

WAVE-PARTICLE DUALITY. Katrina Forrestall & Emily Kingsbury WAVE-PARTICLE DUALITY Katrina Forrestall & Emily Kingsbury History of Light Newton s Particle Model: Newton proposed that light is made up of extremely small particles that travel extremely fast Proposed

More information

6.1.5 Define frequency and know the common units of frequency.

6.1.5 Define frequency and know the common units of frequency. CHM 111 Chapter 6 Worksheet and Study Guide Purpose: This is a guide for your as you work through the chapter. The major topics are provided so that you can write notes on each topic and work the corresponding

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

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

The Atom. Result for Hydrogen. For example: the emission spectrum of Hydrogen: Screen. light. Hydrogen gas. Diffraction grating (or prism)

The Atom. Result for Hydrogen. For example: the emission spectrum of Hydrogen: Screen. light. Hydrogen gas. Diffraction grating (or prism) The Atom What was know about the atom in 1900? First, the existence of atoms was not universally accepted at this time, but for those who did think atoms existed, they knew: 1. Atoms are small, but they

More information

STSF2223 Quantum Mechanics I

STSF2223 Quantum Mechanics I STSF2223 Quantum Mechanics I What is quantum mechanics? Why study quantum mechanics? How does quantum mechanics get started? What is the relation between quantum physics with classical physics? Where is

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

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

Electronic Structure. of Atoms. 2009, Prentice-Hall, Inc. Electronic Structure. of Atoms. 2009, Prentice-Hall, Inc. Electronic Structure.

Electronic Structure. of Atoms. 2009, Prentice-Hall, Inc. Electronic Structure. of Atoms. 2009, Prentice-Hall, Inc. Electronic Structure. Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 6 Section 1 6: The Marathon Adapted from: John D. Bookstaver St. Charles Community College

More information

Supplemental Activities. Module: Atomic Theory. Section: Electromagnetic Radiation and Matter

Supplemental Activities. Module: Atomic Theory. Section: Electromagnetic Radiation and Matter Supplemental Activities Module: Atomic Theory Section: Electromagnetic Radiation and Matter Introduction to Electromagnetic Radiation Activity 1 1. What are the two components that make up electromagnetic

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

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

Energy and the Quantum Theory

Energy and the Quantum Theory Energy and the Quantum Theory Light electrons are understood by comparing them to light 1. radiant energy 2. travels through space 3. makes you feel warm Light has properties of waves and particles Amplitude:

More information

Part One: Light Waves, Photons, and Bohr Theory. 2. Beyond that, nothing was known of arrangement of the electrons.

Part One: Light Waves, Photons, and Bohr Theory. 2. Beyond that, nothing was known of arrangement of the electrons. CHAPTER SEVEN: QUANTUM THEORY AND THE ATOM Part One: Light Waves, Photons, and Bohr Theory A. The Wave Nature of Light (Section 7.1) 1. Structure of atom had been established as cloud of electrons around

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

Historical Background of Quantum Mechanics

Historical Background of Quantum Mechanics Historical Background of Quantum Mechanics The Nature of Light The Structure of Matter Dr. Sabry El-Taher 1 The Nature of Light Dr. Sabry El-Taher 2 In 1801 Thomas Young: gave experimental evidence for

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

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

Electrons in Atoms. Section 5.1 Light and Quantized Energy

Electrons in Atoms. Section 5.1 Light and Quantized Energy Name Date Class 5 Electrons in Atoms Section 5.1 Light and Quantized Energy In your textbook, read about the wave nature of light. Use each of the terms below just once to complete the passage. amplitude

More information

Provide a short and specific definition in YOUR OWN WORDS. Do not use the definition from the book. Electromagnetic Radiation

Provide a short and specific definition in YOUR OWN WORDS. Do not use the definition from the book. Electromagnetic Radiation Name: Provide a short and specific definition in YOUR OWN WORDS. Do not use the definition from the book Additional Notes: Electromagnetic Radiation Electromagnetic Spectrum Wavelength Frequency Photoelectric

More information

DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS

DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS TSOKOS LESSON 1-1B: THE INTERACTION OF MATTER WITH RADIATION Introductory Video Quantum Mechanics Essential Idea: The microscopic quantum world offers

More information

Introduction to Quantum Mechanics (Prelude to Nuclear Shell Model) Heisenberg Uncertainty Principle In the microscopic world,

Introduction to Quantum Mechanics (Prelude to Nuclear Shell Model) Heisenberg Uncertainty Principle In the microscopic world, Introduction to Quantum Mechanics (Prelude to Nuclear Shell Model) Heisenberg Uncertainty Principle In the microscopic world, x p h π If you try to specify/measure the exact position of a particle you

More information

Chapter 2 - Quantum Theory

Chapter 2 - Quantum Theory Chapter - Quantum Theory At the end of this chapter the class will: Have basic concepts of quantum physical phenomena and a rudimentary working knowledge of quantum physics Have some familiarity with quantum

More information

Sparks CH301. Quantum Mechanics. Waves? Particles? What and where are the electrons!? UNIT 2 Day 3. LM 14, 15 & 16 + HW due Friday, 8:45 am

Sparks CH301. Quantum Mechanics. Waves? Particles? What and where are the electrons!? UNIT 2 Day 3. LM 14, 15 & 16 + HW due Friday, 8:45 am Sparks CH301 Quantum Mechanics Waves? Particles? What and where are the electrons!? UNIT 2 Day 3 LM 14, 15 & 16 + HW due Friday, 8:45 am What are we going to learn today? The Simplest Atom - Hydrogen Relate

More information

Wave properties of matter & Quantum mechanics I. Chapter 5

Wave properties of matter & Quantum mechanics I. Chapter 5 Wave properties of matter & Quantum mechanics I Chapter 5 X-ray diffraction Max von Laue suggested that if x-rays were a form of electromagnetic radiation, interference effects should be observed. Crystals

More information

Properties 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? 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

A more comprehensive theory was needed. 1925, Schrödinger and Heisenberg separately worked out a new theory Quantum Mechanics.

A more comprehensive theory was needed. 1925, Schrödinger and Heisenberg separately worked out a new theory Quantum Mechanics. Ch28 Quantum Mechanics of Atoms Bohr s model was very successful to explain line spectra and the ionization energy for hydrogen. However, it also had many limitations: It was not able to predict the line

More information

Chapter 38 Quantum Mechanics

Chapter 38 Quantum Mechanics Chapter 38 Quantum Mechanics Units of Chapter 38 38-1 Quantum Mechanics A New Theory 37-2 The Wave Function and Its Interpretation; the Double-Slit Experiment 38-3 The Heisenberg Uncertainty Principle

More information

PHY202 Quantum Mechanics. Topic 1. Introduction to Quantum Physics

PHY202 Quantum Mechanics. Topic 1. Introduction to Quantum Physics PHY202 Quantum Mechanics Topic 1 Introduction to Quantum Physics Outline of Topic 1 1. Dark clouds over classical physics 2. Brief chronology of quantum mechanics 3. Black body radiation 4. The photoelectric

More information

Chapter 6: Electronic Structure of Atoms

Chapter 6: Electronic Structure of Atoms Chapter 6: Electronic Structure of Atoms Learning Outcomes: Calculate the wavelength of electromagnetic radiation given its frequency or its frequency given its wavelength. Order the common kinds of radiation

More information

298 Chapter 6 Electronic Structure and Periodic Properties of Elements

298 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 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 Bohr Model of Hydrogen, a Summary, Review

The Bohr Model of Hydrogen, a Summary, Review The Bohr Model of Hydrogen, a Summary, Review Allowed electron orbital radii and speeds: Allowed electron energy levels: Problems with the Bohr Model Bohr s model for the atom was a huge success in that

More information

Bellwork: Calculate the atomic mass of potassium and magnesium

Bellwork: Calculate the atomic mass of potassium and magnesium Bellwork: Calculate the atomic mass of potassium and magnesium Chapter 5 - electrons in atoms Section 5.1: Revising the atomic model What did Ernest Rutherford think about electrons? In Rutherford s model,

More information

Quantum Mechanics. Particle in a box All were partial answers, leading Schrödinger to wave mechanics

Quantum Mechanics. Particle in a box All were partial answers, leading Schrödinger to wave mechanics Chemistry 4521 Time is flying by: only 15 lectures left!! Six quantum mechanics Four Spectroscopy Third Hour exam Three statistical mechanics Review Final Exam, Wednesday, May 4, 7:30 10 PM Quantum Mechanics

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