Wavelength of 1 ev electron

Save this PDF as:

Size: px
Start display at page:

Transcription

1 HW8: M Chap 15: Question B, Exercises 2, 6 M Chap 16: Question B, Exercises 1 M Chap 17: Questions C, D From Last Time Essay topic and paragraph due Friday, Mar. 24 Light waves are particles and matter particles are waves! Electromagnetic radiation (e.g. light) made up of photon PARTICLES with energy E=hf and momentum p=e/c=h/ λ Matter particles are waves with wavelength λ=h/p. Wavelength of 1 ev electron For an electron, " = rest energy 1 ev electron, 1240 ev # nm 2 \$ MeV 10 ev electron 100 ev electron constant 1 E kinetic λ=1.23 nm λ=0.39 nm λ=0.12 nm = 1.23 ev 1/ 2 # nm E kinetic kinetic energy Wed. Mar. 22, 2006 Phy107 Lect 23 1 Wed. Mar. 22, 2006 Phy107 Lect 23 2 Question A 10 ev electron has a wavelength of ~ 0.4 nm. What is the wavelength of a 40 ev electron? Can this be correct? If electrons are waves, they should demonstrate wave-like effects e.g. Interference, diffraction A. 0.2 nm B. 0.4 nm C. 0.8 nm A 25 ev electron has wavelength 0.25 nm, similar to atomic spacings in crystals Wavelength = constant rest energy Kinetic energy Wed. Mar. 22, 2006 Phy107 Lect 23 3 Wed. Mar. 22, 2006 Phy107 Lect 23 4 Wave reflection from crystal Reflection from next plane Reflection from top plane Constructive & Destructive Interference Interference arises when waves change their phase relationship. Can vary phase relationship of two waves by changing physical location of speaker. in-phase 1/2 λ phase diff side view Interference of waves reflecting from different atomic layers in the crystal. Difference in path length ~ spacing between atoms Wed. Mar. 22, 2006 Phy107 Lect 23 5 Constructive Destructive Wed. Mar. 22, 2006 Phy107 Lect

2 X-ray diffraction Molecular structure Diffraction spot arrangement indicates atomic arrangement Used to determine atomic arrangements of complex molecules. e.g. DNA Davisson-Germer experiment Diffraction of electrons from a nickel single crystal. Established that electrons are waves Bright spot: constructive Davisson: Nobel Prize 1937 X-ray diffraction pattern 54 ev electrons (λ=0.17nm) Wed. Mar. 22, 2006 Phy107 Lect 23 7 Wed. Mar. 22, 2006 Phy107 Lect 23 8 Suppose an electron is a wave Analogy with sound Here is a wave: " = h p Sound wave also has the same characteristics But we can often locate sound waves E.g. echoes bounce from walls. Can make a sound pulse λ where is the electron? Wave extends infinitely far in +x and -x direction x Example: Hand clap: duration ~ 0.01 seconds Speed of sound = 340 m/s Spatial extent of sound pulse = 3.4 meters. 3.4 meter long hand clap travels past you at 340 m/s Wed. Mar. 22, 2006 Phy107 Lect 23 9 Wed. Mar. 22, 2006 Phy107 Lect Beat frequency: spatial localization What does a sound particle look like? One example is a beat frequency between two notes Two sound waves of almost same wavelength added. Making a particle out of waves 440 Hz Hz 440 Hz Hz Hz Constructive Large amplitude Destructive Small amplitude Constructive Large amplitude Wed. Mar. 22, 2006 Phy107 Lect Hz Hz Hz Hz Hz Wed. Mar. 22, 2006 Phy107 Lect

3 Spatial extent of localized sound wave J Δx = spatial spread of wave packet Spatial extent decreases as the spread in included wavelengths increases. Wed. Mar. 22, 2006 Phy107 Lect Δx Same occurs for a matter wave Construct a localized particle by adding together waves with slightly different wavelengths. Since de Broglie says λ = h /p, each of these components has slightly different momentum. We say that there is some uncertainty in the momentum And still don t know exact location of the particle! Wave still is spread over Δx ( uncertainty in position) Can reduce Δx, but at the cost of increasing the spread in wavelength (giving a spread in momentum). Wed. Mar. 22, 2006 Phy107 Lect Interpreting For sound, we would just say that the sound pulse is centered at some position, but has a spread. Can t do that for a quantum-mechanical particle. Many measurements indicate that the electron is indeed a point particle. Interpretation is that the magnitude of electron wavepulse at some point in space determines the probability of finding the electron at that point. Wed. Mar. 22, 2006 Phy107 Lect J Heisenberg Uncertainty Principle Using Δx = position uncertainty Δp = momentum uncertainty Heisenberg showed that the product ( Δx ) ( Δp ) is always greater than ( h / 4π ) Often write this as where h = h 2"! ("x)("p) ~ h/2 is pronounced h-bar Planck s constant Wed. Mar. 22, 2006 Phy107 Lect 23 16! Thinking about uncertainty ("x)("p) ~ h/2 For a classical particle, p=mv, so an uncertainty in momentum corresponds to an uncertainty in velocity.! ("x)("v) ~ h /2m This says that the uncertainty is small for massive objects, but becomes important for very light objects, such as electrons.! Large, massive objects don t show effects of quantum mechanics. Uncertainty principle question Suppose an electron is inside a box 1 nm in width. There is some uncertainty in the momentum of the electron. We then squeeze the box to make it 0.5 nm. What happens to the momentum? A. Momentum becomes more uncertain B. Momentum becomes less uncertain C. Momentum uncertainty unchanged Wed. Mar. 22, 2006 Phy107 Lect Wed. Mar. 22, 2006 Phy107 Lect

4 Using quantum mechanics Planetary model of atom Quantum mechanics makes astonishingly accurate predictions of the physical world Can apply to atoms, molecules, solids. An early success was in understanding Structure of atoms Interaction of electromagnetic radiation with atoms Positive charge is concentrated in the center of the atom ( nucleus ) Atom has zero net charge: Positive charge in nucleus cancels negative electron charges. Electrons orbit the nucleus like planets orbit the sun (Attractive) Coulomb force plays role of gravity nucleus electrons Wed. Mar. 22, 2006 Phy107 Lect Wed. Mar. 22, 2006 Phy107 Lect Difference between atoms No net charge to atom number of orbiting negative electrons same as number of positive protons in nucleus Different elements have different number of orbiting electrons Hydrogen: 1 electron Helium: 2 electrons Copper: 29 electrons Uranium: 92 electrons! Organized into periodic table of elements Elements in same column have similar chemical properties Wed. Mar. 22, 2006 Phy107 Lect Wed. Mar. 22, 2006 Phy107 Lect Planetary model and radiation Circular motion of orbiting electrons causes them to emit electromagnetic radiation with frequency equal to orbital frequency. Same mechanism by which radio waves are emitted by electrons in a radio transmitting antenna. In an atom, the emitted electromagnetic wave carries away energy from the electron. Electron predicted to continually lose energy. The electron would eventually spiral into the nucleus However most atoms are stable! Atoms and photons Experimentally, atoms do emit electromagnetic radiation, but not just any radiation! In fact, each atom has its own fingerprint of different light frequencies that it emits. 400 nm 500 nm 600 nm 700 nm Hydrogen Mercury Wavelength (nm) Wed. Mar. 22, 2006 Phy107 Lect Wed. Mar. 22, 2006 Phy107 Lect

5 Hydrogen emission spectrum Hydrogen is simplest atom One electron orbiting around one proton. The Balmer Series of emission lines empirically given by Hydrogen emission This says hydrogen emits only photons of a particular wavelength, frequency Photon energy = hf, so this means a particular energy. n = 4, λ = nm Hydrogen n = 3, λ = nm Conservation of energy: Energy carried away by photon is lost by the orbiting electron. Wed. Mar. 22, 2006 Phy107 Lect Wed. Mar. 22, 2006 Phy107 Lect The Bohr hydrogen atom Retained planetary picture: one electron orbits around one proton Only certain orbits are stable Radiation emitted only when electron jumps from one stable orbit to another. Here, the emitted photon has an energy of E initial -E final Stable orbit #2 Stable orbit #1 E initial E final Wed. Mar. 22, 2006 Phy107 Lect Photon Energy levels Instead of drawing orbits, we can just indicate the energy an electron would have if it were in that orbit. Zero energy E 3 = " ev E 2 = " ev E 1 = " ev Wed. Mar. 22, 2006 Phy107 Lect Energy axis Photon emitted hf=e 2 -E 1 Emitting and absorbing light Photon is emitted when electron drops from one quantum state to another Zero energy E 3 = " ev E 2 = " ev E 1 = " ev Photon absorbed hf=e 2 -E 1 E 2 = " ev Wed. Mar. 22, 2006 Phy107 Lect E 3 = " ev E 1 = " ev Absorbing a photon of correct energy makes electron jump to higher quantum state. Photon emission question An electron can jump between the allowed quantum states (energy levels) in a hydrogen atom. The lowest three energy levels of an electron in a hydrogen atom are ev, -3.4 ev, -1.5 ev. These are part of the sequence E n = -13.6/n 2 ev. Which of the following photons could be emitted by the hydrogen atom? A ev B. 3.4 ev C. 1.7 ev The energy carried away by the photon must be given up by the electron. The electron can give up energy by dropping to a lower energy state. So possible photon energies correspond to differences between electron orbital energies. The 10.2 ev photon is emitted when the electron jumps from the -3.4 ev state to the ev state, losing 10.2 ev of energy. Wed. Mar. 22, 2006 Phy107 Lect

6 Energy conservation for Bohr atom Each orbit has a specific energy E n =-13.6/n 2 Photon emitted when electron jumps from high energy to low energy orbit. E i E f = h f Photon absorption induces electron jump from low to high energy orbit. E f E i = h f Agrees with experiment! Wed. Mar. 22, 2006 Phy107 Lect Example: the Balmer series All transitions terminate at the level Each energy level has energy E n =-13.6 / n 2 ev E.g. to transition Emitted photon has energy ## E photon = " 13.6 & # % ( " " 13.6 && % % ( \$ \$ 3 2 ' \$ 2 2 ( =1.89 ev '' Emitted wavelength E photon = hf = hc ", " = hc 1240 ev # nm = = 656 nm E photon 1.89 ev Wed. Mar. 22, 2006 Phy107 Lect Spectral Question Compare the wavelength of a photon produced from a transition from to with that of a photon produced from a transition to. A. λ 31 < λ 21 B. λ 31 = λ 21 C. λ 31 > λ 21 E 31 > E 21 so λ 31 < λ 21 Wed. Mar. 22, 2006 Phy107 Lect

( ) # velocity. Wavelengths of massive objects. From Last Time. Wavelength of electron. Wavelength of 1 ev electron. A little complicated ( ) " = h mv

From Last Time Wavelengths of massive objects Light shows both particle and wavelike properties Matter shows both particle and wavelike properties. How can we make sense of this? debroglie wavelength =

From 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

From Last Time. Summary of Photoelectric effect. Photon properties of light

Exam 3 is Tuesday Nov. 25 5:30-7 pm, 203 Ch (here) Students w / scheduled academic conflict please stay after class Tues. Nov. 8 (TODAY) to arrange alternate time. From Last Time Photoelectric effect and

Title / paragraph example Topic: Quantum Computers. Course Essay. Photoelectric effect summary. From Last Time. Compton scattering

Course Essay 500-750 word typed essay due Wed. Apr. 26 First deadline: Fri. this week (Mar. 24) turn in Topic and Paragraph Description Topic ideas: Nobel prize winner: work & importance Big science project:

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.

Title / paragraph example Topic: Quantum Computers. Course essay. Photoelectric effect summary. From Last Time. Photon interference?

Course essay Friday, Nov 3: Due in class essay topic(review article, operating experiment, noble prize) short description - one paragraph http://www.hep.wisc.edu/~herndon/107-0609/essay.htm Friday, Nov

General 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

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."

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

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

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

Atoms. Radiation from atoms and molecules enables the most accurate time and length measurements: Atomic clocks

Atoms Quantum physics explains the energy levels of atoms with enormous accuracy. This is possible, since these levels have long lifetime (uncertainty relation for E, t). Radiation from atoms and molecules

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

Energy levels. From Last Time. Emitting and absorbing light. Hydrogen atom. Energy conservation for Bohr atom. Summary of Hydrogen atom

From Last Time Hydrogen atom: One electron orbiting around one proton (nucleus) Electron can be in different quantum states Quantum states labeled by integer,2,3,4, In each different quantum state, electron

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

Chapter 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

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

Quick Review. 1. Kinetic Molecular Theory. 2. Average kinetic energy and average velocity. 3. Graham s Law of Effusion. 4. Real Gas Behavior.

Quick Review 1. Kinetic Molecular Theory. 2. Average kinetic energy and average velocity. 3. Graham s Law of Effusion. 4. Real Gas Behavior. Emission spectra Every element has a unique emission spectrum

A fluorescent tube is filled with mercury vapour at low pressure. After mercury atoms have been excited they emit photons.

Q1.(a) A fluorescent tube is filled with mercury vapour at low pressure. After mercury atoms have been excited they emit photons. In which part of the electromagnetic spectrum are these photons? What is

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

CHM 111 Unit 7 Sample Questions

Name: Class: Date: As you work these problems, consider and explain: A. What type of question is it? B. How do you know what type of question it is? C. What information are you looking for? D. What information

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

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

10/27/2017 [pgs ]

Objectives SWBAT explain the relationship between energy and frequency. SWBAT predict the behavior of and/or calculate quantum and photon energy from frequency. SWBAT explain how the quantization of energy

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

hf = E 1 - E 2 hc = E 1 - E 2 λ FXA 2008 Candidates should be able to : EMISSION LINE SPECTRA

1 Candidates should be able to : EMISSION LINE SPECTRA Explain how spectral lines are evidence for the existence of discrete energy levels in isolated atoms (i.e. in a gas discharge lamp). Describe the

Wave nature of particles

Wave nature of particles We have thus far developed a model of atomic structure based on the particle nature of matter: Atoms have a dense nucleus of positive charge with electrons orbiting the nucleus

Quantum Mechanics. Exam 3. Photon(or electron) interference? Photoelectric effect summary. Using Quantum Mechanics. Wavelengths of massive objects

Exam 3 Hour Exam 3: Wednesday, November 29th In-class, Quantum Physics and Nuclear Physics Twenty multiple-choice questions Will cover:chapters 13, 14, 15 and 16 Lecture material You should bring 1 page

WHAT DOES THE ATOM REALLY LOOK LIKE? THE THOMSON MODEL

WHAT DOES THE ATOM REALLY LOOK LIKE? THE THOMSON MODEL RUTHERFORD SCATTERING RUTHERFORD SCATTERING: SOME DETAILS RUTHERFORD SCATTERING: FINAL RESULTS N() = no. scattered into interval to +d N i = total

College Physics B - PHY2054C

of College - PHY2054C The of 11/17/2014 My Office Hours: Tuesday 10:00 AM - Noon 206 Keen Building Outline of 1 2 of 3 4 of Puzzling The blackbody intensity falls to zero at both long and short wavelengths,

Chemistry. Slide 1 / 72. Slide 2 / 72. Slide 3 / 72. Atomic Structures Practice Problems

Slide 1 / 72 Slide 2 / 72 Chemistry Atomic Structures Practice Problems 2015-10-27 www.njctl.org 1 According to Einstein s view of matter and energy, what is the common link between light and matter? Slide

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

DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS

DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS TSOKOS LESSON 6-5: QUANTUM THEORY AND THE UNCERTAINTY PRINCIPLE Introductory Video Quantum Mechanics IB Assessment Statements Topic 13.1, Quantum Physics:

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

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

Explain how line spectra are produced. In your answer you should describe:

The diagram below shows the line spectrum of a gas. Explain how line spectra are produced. In your answer you should describe: how the collisions of charged particles with gas atoms can cause the atoms

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

The Description of the microscopic world

The Description of the microscopic worl This Friay Honor lecture Previous Lecture: Quantization of light, photons Photoelectric effect Particle-Wave ualism Catherine Woowar Botany Photosynthesis This Lecture:

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,

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

Lecture 4. The Bohr model of the atom. De Broglie theory. The Davisson-Germer experiment

Lecture 4 The Bohr model of the atom De Broglie theory The Davisson-Germer experiment Objectives Learn about electron energy levels in atoms and how Bohr's model can be used to determine the energy levels

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

The wavefunction ψ for an electron confined to move within a box of linear size L = m, is a standing wave as shown.

1. This question is about quantum aspects of the electron. The wavefunction ψ for an electron confined to move within a box of linear size L = 1.0 10 10 m, is a standing wave as shown. State what is meant

Do Now: Bohr Diagram, Lewis Structures, Valence Electrons 1. What is the maximum number of electrons you can fit in each shell?

Chemistry Ms. Ye Name Date Block Do Now: Bohr Diagram, Lewis Structures, Valence Electrons 1. What is the maximum number of electrons you can fit in each shell? 1 st shell 2 nd shell 3 rd shell 4 th shell

Bohr. Electronic Structure. Spectroscope. Spectroscope

Bohr Electronic Structure Bohr proposed that the atom has only certain allowable energy states. Spectroscope Using a device called a it was found that gaseous elements emitted electromagnetic radiation

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

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

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

Franck-Hertz experiment, Bohr atom, de Broglie waves Announcements:

Franck-Hertz experiment, Bohr atom, de Broglie waves Announcements: Problem solving sessions Tues. 1-3. Reading for Wednesday TZD 6.1-.4 2013 Nobel Prize Announcement Tomorrow Few slides on the Higgs Field

General Physics (PHY 2140)

General Physics (PHY 2140) Lecture 32 Modern Physics Atomic Physics Early models of the atom Atomic spectra http://www.physics.wayne.edu/~apetrov/phy2140/ Chapter 28 1 If you want to know your progress

The ELECTRON: Wave Particle Duality

The ELECTRON: Wave Particle Duality No familiar conceptions can be woven around the electron. Something unknown is doing we don t know what. -Sir Arthur Eddington The Nature of the Physical World (1934)

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

PHYS 3313 Section 001 Lecture #16

PHYS 3313 Section 001 Lecture #16 Monday, Mar. 24, 2014 De Broglie Waves Bohr s Quantization Conditions Electron Scattering Wave Packets and Packet Envelops Superposition of Waves Electron Double Slit

Physics 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

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

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

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

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:

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

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

Chapters 28 and 29: Quantum Physics and Atoms Questions & Problems

Chapters 8 and 9: Quantum Physics and Atoms Questions & Problems hc = hf = K = = hf = ev P = /t = N h h h = = n = n, n = 1,, 3,... system = hf photon p mv 8 ml photon max elec 0 0 stop total photon 91.1nm

Atomic Structure. Chapter 2

Atomic Structure Chapter 2 Question.. Which of the following contains more electrons than neutrons? H-2 B-11 [O-16] 2- [F-19] 1- The Mass Spectrometer an instrument used to measure masses of different

LECTURE # 17 Modern Optics Matter Waves

PHYS 270-SPRING 2011 LECTURE # 17 Modern Optics Matter Waves April 5, 2011 1 Spectroscopy: Unlocking the Structure of Atoms There are two types of spectra, continuous spectra and discrete spectra: Hot,

Particle 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

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

Physics 1161: Lecture 22

Physics 1161: Lecture 22 Blackbody Radiation Photoelectric Effect Wave-Particle Duality sections 30-1 30-4 Everything comes unglued The predictions of classical physics (Newton s laws and Maxwell s equations)

LECTURE 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

Light & Matter Interactions

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

Chemistry 1B-01, Fall 2012 Lectures 1-2. Chemistry 1B. Fall lectures 1-2. (ch 12 pp ) 6th [ch 12 pp ] 7th

Chemistry 1B Fall 2012 lectures 1-2 (ch 12 pp 522-536) 6th [ch 12 pp 522-537] 7th 20 goals of lectures 1-2 The laws of nature in 1900 (successful for describing large objects) describe particles AND describe

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,

PHY293 Lecture #15. November 27, Quantum Mechanics and the Atom

PHY293 Lecture #15 November 27, 2017 1. Quantum Mechanics and the Atom The Thompson/Plum Pudding Model Thompson discovered the electron in 1894 (Nobel Prize in 1906) Heating materials (metals) causes corpuscles

SPARKS CH301. Why are there no blue fireworks? LIGHT, ELECTRONS & QUANTUM MODEL. UNIT 2 Day 2. LM15, 16 & 17 due W 8:45AM

SPARKS CH301 Why are there no blue fireworks? LIGHT, ELECTRONS & QUANTUM MODEL UNIT 2 Day 2 LM15, 16 & 17 due W 8:45AM QUIZ: CLICKER QUESTION Which of these types of light has the highest energy photons?

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

PHYSICS 102N Spring Week 11 Light emission and absorption

PHYSICS 102N Spring 2009 Week 11 Light emission and absorption Accelerated charges emit electromagnetic waves *) Examples: Radio antenna: Alternating voltage drives electrons back and forth 94.9 million

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

Quantum Physics Lecture 3

Quantum Physics Lecture 3 If light (waves) are particle-like, are particles wave-like? Electron diffraction - Davisson & Germer Experiment Particle in a box -Quantisation of energy Wave Particle?? Wave

Physics 107: Ideas of Modern Physics

Physics 107: Ideas of Modern Physics Exam 3 Nov. 30, 2005 Name ID # Section # On the Scantron sheet, 1) Fill in your name 2) Fill in your student ID # (not your social security #) 3) Fill in your section

Ex: N has 5 valence electrons, so it s Lewis structure would look like: N

Chemistry Ms. Ye Review: Bohr Model of the Atom Name Date Block Electrons are shown in concentric shells or energy levels around the nucleus o The first shell can hold up to o The second shell can hold

PHYS General Physics II Lab The Balmer Series for Hydrogen Source. c = speed of light = 3 x 10 8 m/s

PHYS 1040 - General Physics II Lab The Balmer Series for Hydrogen Source Purpose: The purpose of this experiment is to analyze the emission of light from a hydrogen source and measure and the wavelengths

Wave Nature of Matter. Wave Nature of Matter. Wave Nature of Matter. Light has wave-like and particle-like properties

Wave Nature of Matter Light has wave-like and particle-like properties Can matter have wave and particle properties? de Broglie s hypothesis: matter has wave-like properties in addition to the expected

PHYS 3313 Section 001 Lecture #14

PHYS 3313 Section 001 Lecture #14 Monday, March 6, 2017 The Classic Atomic Model Bohr Radius Bohr s Hydrogen Model and Its Limitations Characteristic X-ray Spectra 1 Announcements Midterm Exam In class

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

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

ATOMIC STRUCTURE. Kotz Ch 7 & Ch 22 (sect 4,5)

ATOMIC STRUCTURE Kotz Ch 7 & Ch 22 (sect 4,5) properties of light spectroscopy quantum hypothesis hydrogen atom Heisenberg Uncertainty Principle orbitals ELECTROMAGNETIC RADIATION subatomic particles (electron,

Wave Nature of Matter

Wave Nature of Matter Wave-Particle Duality de Broglie proposed that particles with momentum could have an associated wavelength (converse of photons having momentum) de Broglie wavelength h λ = p or p

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

Different energy levels

Different energy levels In the microscopic world energy is discrete www.cgrahamphysics.com Review Atomic electrons can only exist in certain discrete energy levels Light is made of photons When e s lose

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,

SECTION A Quantum Physics and Atom Models

AP Physics Multiple Choice Practice Modern Physics SECTION A Quantum Physics and Atom Models 1. Light of a single frequency falls on a photoelectric material but no electrons are emitted. Electrons may

The Wave Nature of Light Made up of. Waves of fields at right angles to each other. Wavelength = Frequency =, measured in

Chapter 6 Electronic Structure of Atoms The Wave Nature of Light Made up of. Waves of fields at right angles to each other. Wavelength = Frequency =, measured in Kinds of EM Waves There are many different

Physics 126 Practice Exam #4 Professor Siegel

Physics 126 Practice Exam #4 Professor Siegel Name: Lab Day: 1. Light is usually thought of as wave-like in nature and electrons as particle-like. In which one of the following instances does light behave

Atoms and Spectroscopy

Atoms and Spectroscopy Lecture 3 1 ONE SMALL STEP FOR MAN ONE GIANT LEAP FOR MANKIND 2 FROM ATOMS TO STARS AND GALAXIES HOW DO WE KNOW? Observations The Scientific Method Hypothesis Verifications LAW 3

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

It s a wave. It s a particle It s an electron It s a photon. It s light!

It s a wave It s a particle It s an electron It s a photon It s light! What they expected Young s famous experiment using a beam of electrons instead of a light beam. And, what they saw Wave-Particle Duality

Atomic 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

Chapter 4. Development of a New Model

Chapter 4 Development of a New Model Electrons behave like particles in some experiments, and like waves in others. The electron's 'wave/particle duality' has no real analogy in the everyday world. The

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

Earlier 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