The Bohr Model of Hydrogen, a Summary, Review

Size: px
Start display at page:

Download "The Bohr Model of Hydrogen, a Summary, Review"

Transcription

1 The Bohr Model of Hydrogen, a Summary, Review Allowed electron orbital radii and speeds: Allowed electron energy levels:

2 Problems with the Bohr Model Bohr s model for the atom was a huge success in that it could explain the spectrum of Hydrogen to very high precision. However, it left many important questions unanswered. For example: Multiple Electron Atoms: When applied to atoms with more than one electron, the model failed to reproduce spectra. Arnold Sommerfeld developed theories that included elliptical orbits, but these didn t work. (Bohr s model does work for any one electron ion, like singly ionized Helium.) The Intensities of Spectral Lines: Why are some emission lines brighter than others? This means that some electron transitions are more probable than others. Bohr says nothing about this. Also, some of these lines are actually closely spaced multiple lines fine structure. Postulates: Ultimately, the Bohr Model gets some things right and gives a useful mental picture of the atom, but as for a model of the atom, it is wrong. However, the postulate question leads us in the right path.

3 de Broglie and his Waves Recall what we have for a photon: (from special relativity*) In 1923, Louis de Broglie (in his PhD thesis!) proposed that the above equations hold for all objects even particles have wave properties! What motivated de Broglie s thinking? No experiment had been done indicating that particles like electrons behave like waves. He was more inspired by symmetry in nature: If photons have particle properties, shouldn t particles, like electrons, have wave properties? So, for every particle, there is an associated wavelength: *Don t use the equation p = E/c for particles. The E in this equation must be the total relativistic energy which is hf for a photon, but is not the kinetic energy for particles. For particles, use wavelength = h/p.

4 Whiteboard QM-7: de Broglie Wavelength Part 1: What kind of numbers are we talking about? Consider a bullet: Calculate the de Broglie wavelength of the bullet in meters. (LC) If we wanted to do an experiment to demonstrate the wave nature (e.g. diffraction) of this bullet, what would we have to do? We should pass the bullet through a hole about the same size as the wavelength! Part 2: The spacing between atoms in a crystal solid is on the order of 1 nm. What kinetic energy (in ev) should an electron have so that its wave properties can be observed when passing through or reflecting from this crystal solid? (LC) Solution: It is very easy to produce electrons in the laboratory with kinetic energies of a few ev. The wave nature of electrons was demonstrated experimentally (by accident) by Davisson and Germer in 1927.

5 How did de Broglie know that he was on to something really big? De Broglie realized this connection between his wavelength and the Bohr theory of hydrogen: The allowed electron orbits in the hydrogen atom are those orbits for which the circumference contain an integral number of de Broglie wavelengths, i.e. circular standing waves. For any Bohr orbit (any n), de Broglie says: (Bohr s angular momentum postulate!) PhET H-atom But, is an electron a particle or a wave? And, if it has wave properties, what is doing the waving? Cass_qm_debr

6 Whiteboard Problem: QM-8 The diameter of the atomic nucleus is about 10 fm. A simple model of the nucleus is that protons and neutrons are confined in a one dimensional box of length 10 fm. Consider a proton in such a box: a) What are the first three energy levels of the proton (in MeV)? Hint: Find the three longest wavelengths that can form a standing wave in the box of length, L = 10 fm. Then use these wavelengths to find the kinetic energies. b) What is the wavelength (in nm) of a photon that is emitted by a nucleus when the proton makes a transition for the n = 2 to the n =1 state? (LC) What type of electromagnetic radiation is this?

7 Quantum Mechanics Everything that we covered up to this point (especially the Bohr atom) falls in the category of Old Quantum Mechanics. We re now ready to start to use what the old quantum mechanics reveals to develop what is known today as Quantum Mechanics. We start with de Broglie s discovery that particles have wave properties, and ask: If a particle has wave properties, What is doing the waving? An Assertion (formally it s a postulate of quantum mechanics): Where did such an idea come from?

8 Quantum Mechanics What should a wave function for a free particle in 1D look like? Classically, a particle of mass m has a position, x, and momentum, p: In QM, what if we use a travelling sinusoidal wave to represent the particle in 1D? Now for the particle: But, where is the particle located? (a well-defined momentum) The particle is equally likely to be anywhere on the x-axis! For a sinusoidal wave: our knowledge of p is perfect: But, our knowledge of x is totally imperfect:

9 Quantum Mechanics - HUP To represent a free particle, we would like a wave that looks like this: small amplitude where the particle isn t. large amplitude where the particle is located. To get a wave packet like this, you have to add together many many waves of different wavelengths, and So, to get more knowledge of the particle s position, we must lose knowledge of it s momentum. (position of particle is somewhere in here) Heisenberg Uncertainty Principle (HUP): In 1927, Werner Heisenberg quantified this relation between how well you can simultaneously know the position and momentum of a particle: Important point: HUP is not a statement about instrument imperfection and how well we can measure things in the lab. It is an inherent property of the particle due to its wave characteristics. Cass_qm_heis

10 Whiteboard QM-9: HUP Can a particle confined in a 1D box of width L have zero energy? Use the HUP to find an expression for the minimum kinetic energy of the particle. (LC) (does this look familiar?) More: Think of the Hydrogen atom; the electron is confined in a region of space, can it have zero energy?

11 Extra QM Credit Quiz: What if h was Bigger? In a minute, we re going to have you take a basic physics evaluation test, and we want to give you some reward for it. So go to MP and begin the QM extra credit quiz. HUP shows that if a particle of mass m is confined (in 1D) to a region of space L that the particle s minimum kinetic energy is For a macroscopic object, this a very tiny energy. But, what if h was bigger, say h = 1000 J. s? Suppose a 50 kg person is confined to a region of space with width 1.0 m. Using this value of h, calculate the minimum speed of the person. So, if h was this big, we would want to avoid narrow areas!

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

The Hydrogen Atom According to Bohr

The Hydrogen Atom According to Bohr The Hydrogen Atom According to Bohr The atom We ve already talked about how tiny systems behave in strange ways. Now let s s talk about how a more complicated system behaves. The atom! Physics 9 4 Early

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

LECTURE 23 SPECTROSCOPY AND ATOMIC MODELS. Instructor: Kazumi Tolich

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

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

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

Wave nature of particles

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

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

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

Wavelength of 1 ev electron

Wavelength of 1 ev electron 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

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

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

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

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

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 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

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

In the early years of the twentieth century, Max Planck, Albert Einstein, Louis de Broglie, Neils

In the early years of the twentieth century, Max Planck, Albert Einstein, Louis de Broglie, Neils Chapter 2 The Early History of Quantum Mechanics In the early years of the twentieth century, Max Planck, Albert Einstein, Louis de Broglie, Neils Bohr, Werner Heisenberg, Erwin Schrödinger, Max Born,

More information

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

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 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 information

The Bohr Model of Hydrogen

The Bohr Model of Hydrogen The Bohr Model of Hydrogen Suppose you wanted to identify and measure the energy high energy photons. One way to do this is to make a calorimeter. The CMS experiment s electromagnetic calorimeter is made

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) In the equation E = hf, the f stands for 1) A) the smaller wavelengths of visible light. B) wave

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

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

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

More information

λ = h = h p mv λ = h mv FXA 2008 Candidates should be able to :

λ = h = h p mv λ = h mv FXA 2008 Candidates should be able to : 1 Candidates should be able to : Explain electron diffraction as evidence for the wave nature of particles like electrons. Explain that electrons travelling through polycrystalline graphite will be diffracted

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

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

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

Chapter 4: The Wave Nature of Matter

Chapter 4: The Wave Nature of Matter Chapter 4: The Wave Nature of Matter q We have seen in Chap. 3 that EM radiation displays both wave properties (classical description) and particle properties (quantum description) q Matter is described

More information

Physics 1C Lecture 29B

Physics 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 information

Lecture 8: Wave-Particle Duality. Lecture 8, p 2

Lecture 8: Wave-Particle Duality. Lecture 8, p 2 We choose to examine a phenomenon which is impossible, absolutely impossible, to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery.

More information

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. 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

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

PHYSICS 102N Spring Week 12 Quantum Mechanics and Atoms

PHYSICS 102N Spring Week 12 Quantum Mechanics and Atoms PHYSICS 102N Spring 2009 Week 12 Quantum Mechanics and Atoms Quantum Mechanics 1. All objects can be represented by waves describing their propagation through space 2. The wave length is λ=h/p and frequency

More information

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

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

More information

Physics 25 Chapter 29 Dr. Alward

Physics 25 Chapter 29 Dr. Alward Physics 25 Chapter 29 Dr. Alward Photons and Matter Waves Planck s Constant: h = 6.63 x 10-34 J-s E = hf E = hc/λ 1 Example A: Red light of wavelength λ = 720 nm consists of a stream of photons of what

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

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

UNIT 7 ATOMIC AND NUCLEAR PHYSICS

UNIT 7 ATOMIC AND NUCLEAR PHYSICS 1 UNIT 7 ATOMIC AND NUCLEAR PHYSICS PHYS:1200 LECTURE 33 ATOMIC AND NUCLEAR PHYSICS (1) The physics that we have presented thus far in this course is classified as Classical Physics. Classical physics

More information

5.111 Principles of Chemical Science

5.111 Principles of Chemical Science MIT OpenCourseWare http://ocw.mit.edu 5.111 Principles of Chemical Science Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 5.111 Lecture Summary

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

Lecture 21 Matter acts like waves!

Lecture 21 Matter acts like waves! Particles Act Like Waves! De Broglie s Matter Waves λ = h / p Schrodinger s Equation Announcements Schedule: Today: de Broglie and matter waves, Schrodinger s Equation March Ch. 16, Lightman Ch. 4 Net

More information

Physics 1C Lecture 28C. "For those who are not shocked when they first come across quantum theory cannot possibly have understood it.

Physics 1C Lecture 28C. For those who are not shocked when they first come across quantum theory cannot possibly have understood it. Physics 1C Lecture 28C "For those who are not shocked when they first come across quantum theory cannot possibly have understood it." --Neils Bohr Outline CAPE and extra credit problems Wave-particle duality

More information

General Physics (PHY 2140)

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

More information

Heat of formation / enthalpy of formation!

Heat of formation / enthalpy of formation! 165 Heat of formation / enthalpy of formation! What is the enthalpy change at standard conditions when 25.0 grams of hydrogen sulfide gas is reacted? 1 - Use Hess' Law to find the enthalpy change of the

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

Physics 126 Practice Exam #4 Professor Siegel

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

More information

Physics 222, Modern Physics, Exam 1 NAME

Physics 222, Modern Physics, Exam 1 NAME Physics 222, Modern Physics, Exam 1 NAME You are graded on your work, with partial credit where it is deserved. Please be clear and well-organized in all your steps. 1. Gold has a work function of 4.83

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

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

Models of the Atom. Spencer Clelland & Katelyn Mason

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

More information

Chapter 38 and Chapter 39

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

More information

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 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?

More information

Chem 6, 10 Section Spring Exam 2 Solutions

Chem 6, 10 Section Spring Exam 2 Solutions Exam 2 Solutions 1. (4 + 6 + 5 points) Dartmouth s FM radio station, WDCR, broadcasts by emitting from its antenna photons of frequency 99.3 MHz (99.3 10 6 Hz). (a) What is the energy of a single WDCR

More information

Calculate the volume of propane gas at 25.0 C and 1.08 atm required to provide 565 kj of heat using the reaction above.

Calculate the volume of propane gas at 25.0 C and 1.08 atm required to provide 565 kj of heat using the reaction above. 167 Calculate the volume of propane gas at 25.0 C and 1.08 atm required to provide 565 kj of heat using the reaction above. 1 - Convert energy requirement to moles PROPANE using thermochemical equation.

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

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

Exercise 1 Atomic line spectra 1/9

Exercise 1 Atomic line spectra 1/9 Exercise 1 Atomic line spectra 1/9 The energy-level scheme for the hypothetical one-electron element Juliettium is shown in the figure on the left. The potential energy is taken to be zero for an electron

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

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

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

College Physics B - PHY2054C

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,

More information

Chapter 27 Lecture Notes

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

More information

Chapter 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

Quantum Physics Lecture 3

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

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

The Discovery of the Wave Nature of the Electron

The Discovery of the Wave Nature of the Electron The Discovery of the Wave Nature of the Electron de Broglie s Theory of Matter Waves Luis Suarez University of South Carolina Louis de Broglie 1892-1987 2 A brief history of light Is it a stream of particles

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

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

Sometimes light acts like a wave Reminder: Schedule changes (see web page)

Sometimes light acts like a wave Reminder: Schedule changes (see web page) Announcements Sometimes light acts like a wave Reminder: Schedule changes (see web page) No class on Thursday 3/18 Exam 2 pushed back to Tues. 3/30 Today: Quantum Mechanics (Ch.13/14) Bright: Constructive

More information

Fundamental of Spectroscopy for Optical Remote Sensing Xinzhao Chu I 10 3.4. Principle of Uncertainty Indeterminacy 0. Expression of Heisenberg s Principle of Uncertainty It is worth to point out that

More information

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 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 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

PHYSICS 3204 PUBLIC EXAM QUESTIONS (Quantum pt.1)

PHYSICS 3204 PUBLIC EXAM QUESTIONS (Quantum pt.1) PHYSICS 3204 PUBLIC EXAM QUESTIONS (Quantum pt.1) NAME: August 2009--------------------------------------------------------------------------------------------------------------------------------- 11 41.

More information

Quantum Mechanics. Physics April 2002 Lecture 9. Planck Bohr Schroedinger Heisenberg

Quantum Mechanics. Physics April 2002 Lecture 9. Planck Bohr Schroedinger Heisenberg Quantum Mechanics Physics 102 18 April 2002 Lecture 9 Planck Bohr Schroedinger Heisenberg From: http://www.th.physik.uni-frankfurt.de/~jr/portraits.html 18 Apr 2002 Physics 102 Lecture 9 1 Blackbody radiation

More information

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

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

More information

The Wave Nature of Matter Causes Quantization *

The Wave Nature of Matter Causes Quantization * OpenStax-CNX module: m60855 1 The Wave Nature of Matter Causes Quantization * OpenStax Physics with Courseware Based on The Wave Nature of Matter Causes Quantization by OpenStax This work is produced by

More information

Lecture 35 (de Broglie & Matter Waves) Physics Fall 2018 Douglas Fields

Lecture 35 (de Broglie & Matter Waves) Physics Fall 2018 Douglas Fields Lecture 35 (de Broglie & Matter Waves) Physics 6-01 Fall 018 Douglas Fields Clicker Quiz For a certain metal, the work function is 4eV. If light at frequency 1.9x10 15 Hz strikes the metal, what is the

More information

QUANTUM MECHANICS Chapter 12

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

More information

Notes for Special Relativity, Quantum Mechanics, and Nuclear Physics

Notes for Special Relativity, Quantum Mechanics, and Nuclear Physics Notes for Special Relativity, Quantum Mechanics, and Nuclear Physics 1. More on special relativity Normally, when two objects are moving with velocity v and u with respect to the stationary observer, the

More information

Chem 467 Supplement to Lecture 19 Hydrogen Atom, Atomic Orbitals

Chem 467 Supplement to Lecture 19 Hydrogen Atom, Atomic Orbitals Chem 467 Supplement to Lecture 19 Hydrogen Atom, Atomic Orbitals Pre-Quantum Atomic Structure The existence of atoms and molecules had long been theorized, but never rigorously proven until the late 19

More information

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

( ) # 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 =

More information

Heat of formation / enthalpy of formation! What is the enthalpy change at standard conditions when 25.0 grams of hydrogen sulfide gas is reacted?

Heat of formation / enthalpy of formation! What is the enthalpy change at standard conditions when 25.0 grams of hydrogen sulfide gas is reacted? 135 Heat of formation / enthalpy of formation! What is the enthalpy change at standard conditions when 25.0 grams of hydrogen sulfide gas is reacted? (Data from Appendix G!) 1) Find the enthalpy of reaction

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

Outline Chapter 9 The Atom Photons Photons The Photoelectron Effect Photons Photons

Outline 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 information

CHAPTER 2: POSTULATES OF QUANTUM MECHANICS

CHAPTER 2: POSTULATES OF QUANTUM MECHANICS CHAPTER 2: POSTULATES OF QUANTUM MECHANICS Basics of Quantum Mechanics - Why Quantum Physics? - Classical mechanics (Newton's mechanics) and Maxwell's equations (electromagnetics theory) can explain MACROSCOPIC

More information

Ch 6 Atomic Spectra. Masterson & Hurley

Ch 6 Atomic Spectra. Masterson & Hurley Ch 6 Atomic Spectra Masterson & Hurley 1 Joule = 1 kg m 2 s 2 Ch 6.1 Light, Photon Energies, & Atomic Spectra What scientists know about light, scientists are able to explain the structure of the atom.

More information

74 My God, He Plays Dice! Chapter 10. Bohr-Einstein Atom

74 My God, He Plays Dice! Chapter 10. Bohr-Einstein Atom 74 My God, He Plays Dice! Bohr-Einstein Atom Bohr Atom Bohr-Einstein Atom Niels Bohr is widely, and correctly, believed to be the third most important contributor to quantum mechanics, after Max Planck

More information

PH300 Spring Homework 07

PH300 Spring Homework 07 PH300 Spring 2011 Homework 07 Total Points: 30 1. (1 Point) Each week you should review both your answers and the solutions for the previous week's homework to make sure that you understand all the questions

More information

29:006 FINAL EXAM FRIDAY MAY 11 3:00 5:00 PM IN LR1 VAN

29:006 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 information

Welcome back to PHY 3305

Welcome back to PHY 3305 Welcome back to PHY 3305 Today s Lecture: Double Slit Experiment Matter Waves Louis-Victor-Pierre-Raymond, 7th duc de Broglie 1892-1987 Double-Slit Experiment Photons pass through the double-slit apparatus.

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

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

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

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

More information

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

An electron can be liberated from a surface due to particle collisions an electron and a photon.

An 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 information

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

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

More information

PHYS 3313 Section 001 Lecture #16

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

More information

Chapter 27. Quantum Physics

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

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

Physics 314 (Survey of Astronomy) Exam 1

Physics 314 (Survey of Astronomy) Exam 1 Physics 314 (Survey of Astronomy) Exam 1 Please show all significant steps clearly in all problems. Please give clear and legible responses to qualitative questions. See the last page for values of constants.

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

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