Physics 2D Lecture Slides Lecture 15: Feb 2nd Vivek Sharma UCSD Physics. Where are the electrons inside the atom?
|
|
- Quentin Rice
- 6 years ago
- Views:
Transcription
1 Physics D Lecture Slides Lecture 15: Feb nd 005 Vivek Sharma UCSD Physics Where are the electrons inside the atom? Early Thought: Plum pudding model Atom has a homogenous distribution of Positive charge with electrons embedded in them (atom is neutral) e - e - e - e e- - e - e - e - e - e - e - e - e - e - e - e - e - e - e - Positively charged matter or? How to test these hypotheses? Shoot bullets at the atom and watch their trajectory. What Kind of bullets? + Core Indestructible charged bullets Ionized He ++ atom = α ++ particles Q = +e, Mass M α =4amu >> m e, V α = x 10 7 m/s (non-relavistic) [charged to probe charge & mass distribution inside atom] + 1
2 Plum Pudding Model of Atom Non-relativistic mechanics (V α /c = 0.1) In Plum-pudding model, α-rays hardly scatter because Positive charge distributed over size of atom (10-10 m) M α >> M e (like moving truck hits a bicycle) predict α-rays will pass thru array of atoms with little scatter (~1 o ) Need to test this hypothesis Ernest Rutherford Probing Within an Atom with α Particles Most α particles pass thru gold foil with nary a deflection SOME ( 10-4 ) scatter at LARGE angles Φ Even fewer scatter almost backwards Why
3 Rutherford Discovers Nucleus (Nobel Prize) Rutherford Scattering discovered by his PhD Student (Marsden) 3
4 Force on α-particle due to heavy Nucleus Outside radius r =R, F Q/r Inside radius r < R, F q/r = Qr/R Maximum force at radius r = R! particle trajectory is hyperbolic Scattering angle is related to impact par. # kq Q $ # " $ = % & % & ' ( ' (! Impact Parameter b cot m! v! Rutherford Scattering: Prediction and Experimental Result # n = 4 k Z e NnA $ 1 % 4!! " 4 R & m v ' Sin ( / ) ( ) # scattered Vs φ depends on : n = # of incident alpha particles N = # of nuclei/area of foil Ze = Nuclear charge K α of incident alpha beam A= detector area 4
5 Rutherford Scattering & Size of Nucleus nucleus nucleus distance of closest appoach # r size of nucleus 1 Kinetic energy of! = K! = m! v"! particle will penetrate thru a radius r until all its kinetic energy is used up to do work AGAINST the Coulomb potential of the Nucleus: 1 m v MeV = k K! =! " = 8 % kze r = K For K =7.7.MeV, Z = 13! kze % r = K Size of Nucleus = 10!! Size of Atom = Al = 4.9& 10 m m ( Ze)( e) r $ 15 m Dimension Matters! Size of Nucleus = 10 Size of Atom = m m how are the electrons located inside an atom How are they held in a stable fashion necessary condition for us to exist! All these discoveries will require new experiments and observations 5
6 Rutherford Atom & Classical Physics? Continuous & Discrete spectra of Elements 6
7 Visible Spectrum of Sun Through a Prism Emission & Absorption Line Spectra of Elements 7
8 Kirchhoff Experiment : D Lines in Na D lines darken noticeably when Sodium vapor introduced Between slit and prism Emission & Absorption Line Spectrum of Elements Emission line appear dark because of photographic exposure Absorption spectrum of Na While light passed thru Na vapor is absorbed at specific λ 8
9 Spectral Observations : series of lines with a pattern Empirical observation (by trial & error) All these series can be summarized in a simple formula 1 $ 1 1 % = R ", n f > ni, ni = 1,,3, 4..! & n f n ' ( i ) Fitting to spectral line series data R= # 10 m 7 " 1 How does one explain this? The Rapidly Vanishing Atom: A Classical Disaster! Not too hard to draw analogy with dynamics under another Central Force Think of the Gravitational Force between two objects and their circular orbits. Perhaps the electron rotates around the Nucleus and is bound by their electrical charge M1M Q1Q F= G! k r r Laws of E&M destroy this equivalent picture : Why? 9
10 Bohr s Bold Model of Atom: Semi Quantum/Classical -e 1. Electron in circular orbit m e around proton with vel=v. Only stationary orbits allowed. Electron does not F V radiate when in these stable +e (stationary) orbits 3. Orbits quantized: r e U ( r) =! k r 1 KE = m v e M e v r = n h/π (n=1,,3 ) 4. Radiation emitted when electron jumps from a stable orbit of higher energy stable orbit of lower energy E f -E i = hf =hc/λ 5. Energy change quantized f = frequency of radiation General Two body Motion under a central force Reduced Mass of -body system +e F -e m e V reduces to r m e Both Nucleus & e - revolve around their common center of mass (CM) Such a system is equivalent to single particle of reduced mass µ that revolves around position of Nucleus at a distance of (e - -N) separation µ= (m e M)/(m e +M), when M>>m, µ=m (Hydrogen atom) Νot so when calculating Muon (m µ = 07 m e ) or equal mass charges rotating around each other (similar to what you saw in gravitation) 10
11 Allowed Energy Levels & Orbit Radii in Bohr Model 1 e E=KE+U = mev! k r Force Equality for Stable Orbit " Coulomb attraction = CP Force e k r mev e " KE = = k r e Total Energy E = KE+U= - k r Negative E " Bound system This much energy must be added to the system to break up the bound atom mev = r Radius of Electron Orbit : mvr = n! n! " v =, mr 1 ke substitute in KE= mev = r n! " rn =, n = 1,,... # mke n = 1" Bohr Radius a 1!! 10 a0 = = 0.59$ 10 m mke In ge = = # neral rn n a0; n 1,,... Quantized orbits of rotation 0 Energy Level Diagram and Atomic Transitions " ke En = K + U = r since r = a n,n =quantum number n 0 Interstate transition: n 0 " ke 13.6 En = = " ev, n = 1,,3.. # a n n + E = hf = E " E i f i * n " ke $ 1 1 % = " a & 0 ni n ' ( f ) ke $ 1 1 % f = " ha & 0 n f n ' ( i ) 1 f ke $ 1 1 % = = "! c hca & 0 ( n f n ' i ) $ 1 1 % = R " & n f n ' ( i ) f 11
12 Hydrogen Spectrum: as explained by Bohr E n! ke " Z = #$ % & a0 ' n Bohr s R same as the Rydberg Constant R derived emperically from photographs of the spectral series Another Look at the Energy levels E n! ke " Z = #$ % & a0 ' n Rydberg Constant 1
13 Bohr s Atom: Emission & Absorption Spectra photon photon Some Notes About Bohr Like Atoms Ground state of Hydrogen atom (n=1) E 0 = ev Method for calculating energy levels etc applies to all Hydrogenlike atoms -1e around +Ze Examples : He +, Li ++ Energy levels would be different if replace electron with Muons Bohr s method can be applied in general to all systems under a central force (e.g. gravitational instead of Coulombic) Q Q M M If change U ( r) = k! G r r Changes every thing: E, r, f etc 1 1 "Importance of constants in your life" 13
14 Bohr s Correspondence Principle It now appears that there are two different worlds with different laws of physics governing them The macroscopic world The microscopic world How does one transcend from one world to the other? Bohr s correspondence Principle predictions of quantum theory must correspond to predictions of the classical physics in the regime of sizes where classical physics is known to hold. when n [Quantum Physics] = [Classical Physics] 14
Physics 2D Lecture Slides Feb. 2, Sunil Sinha UCSD Physics
Physics D Lecture Slides Feb., 010 Sunil Sinha UCSD Physics Thomson s Determination of e/m of the Electron In E Field alone, electron lands at D In B field alone, electron lands at E When E and B field
More information4E : The Quantum Universe. Lecture 6, April 6 Vivek Sharma
4E : The Quantum Universe Lecture 6, April 6 Vivek Sharma modphys@hepmail.ucsd.edu Bragg Scattering photographic film Bragg Scattering: Probing Atoms With X-Rays Incident X-ray detector Constructive Interference
More informationGeneral Physics (PHY 2140)
General Physics (PHY 140) Lecture 33 Modern Physics Atomic Physics Atomic spectra Bohr s theory of hydrogen http://www.physics.wayne.edu/~apetrov/phy140/ Chapter 8 1 Lightning Review Last lecture: 1. Atomic
More informationChapter 28. Atomic Physics
Chapter 28 Atomic Physics Sir Joseph John Thomson J. J. Thomson 1856-1940 Discovered the electron Did extensive work with cathode ray deflections 1906 Nobel Prize for discovery of electron Early Models
More informationChapter 29 Atomic Physics. Looking Ahead. Slide 29-1
Chapter 29 Atomic Physics Looking Ahead Slide 29-1 Atomic Spectra and the Bohr Model In the mid 1800s it became apparent that the spectra of atomic gases is comprised of individual emission lines. Slide
More informationStructure of the Atom. Thomson s Atomic Model. Knowledge of atoms in Experiments of Geiger and Marsden 2. Experiments of Geiger and Marsden
CHAPTER 4 Structure of the Atom 4.1 The Atomic Models of Thomson and Rutherford 4. Rutherford Scattering 4.3 The Classic Atomic Model 4.4 The Bohr Model of the Hydrogen Atom 4.5 Successes & Failures of
More informationParticle Nature of Matter. Chapter 4
Particle Nature of Matter Chapter 4 Modern physics When my grandfather was born, atoms were just an idea. That year, 1897, was marked by the discovery of the electron by J.J. Thomson. The nuclear model
More informationPhysics 1C Lecture 29A. Finish off Ch. 28 Start Ch. 29
Physics 1C Lecture 29A Finish off Ch. 28 Start Ch. 29 Particle in a Box Let s consider a particle confined to a one-dimensional region in space. Following the quantum mechanics approach, we need to find
More informationPhysics 1C. Modern Physics Lecture
Physics 1C Modern Physics Lecture "I ask you to look both ways. For the road to a knowledge of the stars leads through the atom; and important knowledge of the atom has been reached through the stars."
More informationThe 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 informationPHY293 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
More informationLECTURE 23 SPECTROSCOPY AND ATOMIC MODELS. Instructor: Kazumi Tolich
LECTURE 23 SPECTROSCOPY AND ATOMIC MODELS Instructor: Kazumi Tolich Lecture 23 2 29.1 Spectroscopy 29.2 Atoms The first nuclear physics experiment Using the nuclear model 29.3 Bohr s model of atomic quantization
More informationChapter 37 Early Quantum Theory and Models of the Atom
Chapter 37 Early Quantum Theory and Models of the Atom Units of Chapter 37 37-7 Wave Nature of Matter 37-8 Electron Microscopes 37-9 Early Models of the Atom 37-10 Atomic Spectra: Key to the Structure
More informationAtom Physics. Chapter 30. DR JJ UiTM-Cutnell & Johnson 7th ed. 1. Model of an atom-the recent model. Nuclear radius r m
Chapter 30 Atom Physics DR JJ UiTM-Cutnell & Johnson 7th ed. 1 30.1 Rutherford Scattering and the Nuclear Atom Model of an atom-the recent model Nuclear radius r 10-15 m Electron s position radius r 10-10
More informationCLASS 12th. Modern Physics-II
CLASS 12th Modern Physics-II 1. Thomson s Atom Model From the study of discharge of electricity through gases, it became clear that an atom consists of positive and negative charges. As the atom is electrically
More informationGeneral 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
More informationPlanck s Quantum Hypothesis Blackbody Radiation
Planck s Quantum Hypothesis Blackbody Radiation The spectrum of blackbody radiation has been measured(next slide); it is found that the frequency of peak intensity increases linearly with temperature.
More informationModels of the Atom. Spencer Clelland & Katelyn Mason
Models of the Atom Spencer Clelland & Katelyn Mason First Things First Electrons were accepted to be part of the atom structure by scientists in the1900 s. The first model of the atom was visualized as
More information3/29/2010. Structure of the Atom. Knowledge of atoms in 1900 CHAPTER 6. Evidence in 1900 indicated that the atom was not a fundamental unit:
3/9/010 CHAPTER 6 Rutherford Scattering 6.1 The Atomic Models of Thomson and Rutherford 6. Definition of Cross Section 6. Rutherford Scattering 6.3 Structure of the Nucleus The opposite of a correct statement
More informationCHAPTER 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 informationChapter 28. Atomic Physics
Chapter 28 Atomic Physics Quantum Numbers and Atomic Structure The characteristic wavelengths emitted by a hot gas can be understood using quantum numbers. No two electrons can have the same set of quantum
More informationChapter 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 informationLecture PowerPoints. Chapter 27 Physics: Principles with Applications, 7th edition Giancoli
Lecture PowerPoints Chapter 27 Physics: Principles with Applications, 7th edition Giancoli This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching
More informationEarly Quantum Theory & Models of the Atom (Ch 27) Discovery of electron. Blackbody Radiation. Blackbody Radiation. J. J. Thomson ( )
Early Quantum Theory & Models of the Atom (Ch 27) Discovery of electron Modern physics special relativity quantum theory J. J. Thomson (1856-1940) measured e/m directly set-up was similar to mass spectrometer
More informationParticle nature of light & Quantization
Particle nature of light & Quantization A quantity is quantized if its possible values are limited to a discrete set. An example from classical physics is the allowed frequencies of standing waves on a
More informationFinal Exam: Thursday 05/02 7:00 9:00 pm in STEW 183
Final Exam: Thursday 05/02 7:00 9:00 pm in STEW 183 Covers all readings, lectures, homework from Chapters 17 through 30 Be sure to bring your student ID card, calculator, pencil, and up to three onepage
More informationPHYS 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
More informationAtomic Structure. Thornton and Rex, Ch. 4
Atomic Structure Thornton and Rex, Ch. 4 Models of the Atom Required features: 1. Electrons as constituents. 2. Some positive charges to neutralize the negative charges of the electrons. 3. Some scheme
More informationPhysics 102: Lecture 24. Bohr vs. Correct Model of Atom. Physics 102: Lecture 24, Slide 1
Physics 102: Lecture 24 Bohr vs. Correct Model of Atom Physics 102: Lecture 24, Slide 1 Plum Pudding Early Model for Atom positive and negative charges uniformly distributed throughout the atom like plums
More informationFrom 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
More informationAtomic Structure. Thornton and Rex, Ch. 4
Atomic Structure Thornton and Rex, Ch. 4 Models of the Atom Required features: 1. Electrons as constituents. 2. Some positive charges to neutralize the negative charges of the electrons. 3. Some scheme
More informationChapter 37 Early Quantum Theory and Models of the Atom. Copyright 2009 Pearson Education, Inc.
Chapter 37 Early Quantum Theory and Models of the Atom Planck s Quantum Hypothesis; Blackbody Radiation Photon Theory of Light and the Photoelectric Effect Energy, Mass, and Momentum of a Photon Compton
More informationAtomic Models the Nucleus
Atomic Models the Nucleus Rutherford (read his bio on pp 134-5), who had already won a Nobel for his work on radioactivity had also named alpha, beta, gamma radiation, developed a scattering technique
More information3. Particle nature of matter
3. Particle nature of matter 3.1 atomic nature of matter Democrit(us) 470-380 B.C.: there is only atoms and empty space, everything else is mere opinion (atoms are indivisible) Dalton (chemist) 180: chemical
More informationThe 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 informationAtomic Structure. Thornton and Rex, Ch. 4
Atomic Structure Thornton and Rex, Ch. 4 Models of the Atom Required features: 1. Electrons as constituents. 2. Some positive charges to neutralize the negative charges of the electrons. 3. Some scheme
More informationPhysics 116. Nov 22, Session 32 Models of atoms. R. J. Wilkes
Physics 116 Session 32 Models of atoms Nov 22, 2011 Thomson Rutherford R. J. Wilkes Email: ph116@u.washington.edu Announcements Exam 3 next week (Tuesday, 11/29) Usual format and procedures I ll post example
More informationPreview. Atomic Physics Section 1. Section 1 Quantization of Energy. Section 2 Models of the Atom. Section 3 Quantum Mechanics
Atomic Physics Section 1 Preview Section 1 Quantization of Energy Section 2 Models of the Atom Section 3 Quantum Mechanics Atomic Physics Section 1 TEKS The student is expected to: 8A describe the photoelectric
More informationRadiation can be defined as the propagation of energy through matter or space. It can be in the form of electromagnetic waves or energetic particles.
Lecture 1: Overview; History of Radiation Radiation can be defined as the propagation of energy through matter or space. It can be in the form of electromagnetic waves or energetic particles. Source: Lawrence
More informationSpectroscopy. Hot self-luminous objects light the Sun or a light bulb emit a continuous spectrum of wavelengths.
Hot self-luminous objects light the Sun or a light bulb emit a continuous spectrum of wavelengths. In contract, light emitted in low=pressure gas discharge contains only discrete individual wavelengths,
More informationUNIT VIII ATOMS AND NUCLEI
UNIT VIII ATOMS AND NUCLEI Weightage Marks : 06 Alpha-particles scattering experiment, Rutherford s model of atom, Bohr Model, energy levels, Hydrogen spectrum. Composition and size of Nucleus, atomic
More informationPhysics 3223 Solution to Assignment #5
Physics 3223 Solution to Assignment #5 October 20, 1999 6.1 From the Heisenberg uncertainty principle, x p h, we estimate that a typical kinetic energy of an electron in an atom would be K ( p)2 2m h 2
More informationThe 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 informationParticle and Nuclear Physics. Outline. Structure of the Atom. History of Atomic Structure. 1 Structure of the Atom
Outline of 1 of Atomic Spectra of Helium Classical Atom of Existence of spectral lines required new model of atom, so that only certain amounts of energy could be emitted or absorbed. By about 1890, most
More informationThe Atom and Quantum Mechanics
The Atom and Quantum Mechanics Last time... In a spherical geometry the sum of the angles of a triangle > 180 What is the principle of equivalence? What three observations confirmed Einstein s Theory of
More informationTHE UNIVERSITY OF QUEENSLAND DEPARTMENT OF PHYSICS PHYS2041 ATOMIC SPECTROSCOPY
THE UNIVERSITY OF QUEENSLAND DEPARTMENT OF PHYSICS PHYS2041 ATOMIC SPECTROSCOPY Warning: The mercury spectral lamps emit UV radiation. Do not stare into the lamp. Avoid exposure where possible. Introduction
More informationQuantum and Atomic Physics - Multiple Choice
PSI AP Physics 2 Name 1. The Cathode Ray Tube experiment is associated with: (A) J. J. Thomson (B) J. S. Townsend (C) M. Plank (D) A. H. Compton 2. The electron charge was measured the first time in: (A)
More information2/28/2016 ATOMS) ATOMS. Physics 2D. PHYS 342 Modern Physics Atom I: Rutherford Model and Bohr Model
PHYS 342 Modern Physics Atom I: Rutherford Model and Bohr Model Today Contents: a) Basic Properties of Atoms b) Rutherford Model and Scattering Experiments c) Bohr Model and Line Spectra Physics 2D Subfields
More information1 The Cathode Rays experiment is associated. with: Millikan A B. Thomson. Townsend. Plank Compton
1 The Cathode Rays experiment is associated with: A B C D E Millikan Thomson Townsend Plank Compton 1 2 The electron charge was measured the first time in: A B C D E Cathode ray experiment Photoelectric
More informationIntroduction to Nuclei I (The discovery)
Introduction to Nuclei I (The discovery) The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth - Niels Bohr The Atomic Nucleus
More informationQuestion 12.1: Choose the correct alternative from the clues given at the end of the each statement: (a) The size of the atom in Thomson s model is... the atomic size in Rutherford s model. (much greater
More informationLECTURE # 19 Dennis Papadopoulos End of Classical Physics Quantization Bohr Atom Chapters 38 39
PHYS 270-SPRING 2011 LECTURE # 19 Dennis Papadopoulos End of Classical Physics Quantization Bohr Atom Chapters 38 39 April 14, 2011 1 HOW TO MEASURE SPECTRA Spectroscopy: Unlocking the Structure of Atoms
More informationTHE NATURE OF THE ATOM. alpha particle source
chapter THE NATURE OF THE ATOM www.tutor-homework.com (for tutoring, homework help, or help with online classes) Section 30.1 Rutherford Scattering and the Nuclear Atom 1. Which model of atomic structure
More informationPhysics: Quanta to Quarks Option (99.95 ATAR)
HSC Physics Year 2016 Mark 95.00 Pages 22 Published Jan 15, 2017 Physics: Quanta to Quarks Option (99.95 ATAR) By Edward (99.95 ATAR) Powered by TCPDF (www.tcpdf.org) Your notes author, Edward. Edward
More informationLecture 32 April
Lecture 32 April 08. 2016. Hydrogen Discharge Tube and Emission of Discrete Wavelengths Description of the discrete Hydrogen Emission Spectrum by the Balmer (1884) Rydberg Ritz formula (1908) Cathode Ray
More informationAtomic Theory. Developing the Nuclear Model of the Atom. Saturday, January 20, 18
Atomic Theory Developing the Nuclear Model of the Atom Democritus Theory: Atom, the indivisible particle c. 300 BC Democritus Problem: No scientific evidence c. 300 BC Dalton Theory: The solid sphere model
More informationChapters 31 Atomic Physics
Chapters 31 Atomic Physics 1 Overview of Chapter 31 Early Models of the Atom The Spectrum of Atomic Hydrogen Bohr s Model of the Hydrogen Atom de Broglie Waves and the Bohr Model The Quantum Mechanical
More informationPhysics 1C. Lecture 28D
Physics 1C Lecture 28D "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." --Sir Arthur
More informationIntroduction to Nuclei I
Introduction to Nuclei I (The Discovery) The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth - Niels Bohr The Atom (as we know
More informationArvind Borde / PHY 19, Week 8: The Atom
Arvind Borde / PHY 9, Week 8: The Atom 8. Atoms and Molecules 8.. History We now take for granted that matter is made out of atoms, in turn made of electrons, protons, neutrons, but this understanding
More informationChapter 27 Early Quantum Theory and Models of the Atom Discovery and Properties of the electron
Chapter 27 Early Quantum Theory and Models of the Atom 27-1 Discovery and Properties of the electron Measure charge to mass ratio e/m (J. J. Thomson, 1897) When apply magnetic field only, the rays are
More informationThe atom cont. +Investigating EM radiation
The atom cont. +Investigating EM radiation Announcements: First midterm is 7:30pm on Sept 26, 2013 Will post a past midterm exam from 2011 today. We are covering Chapter 3 today. (Started on Wednesday)
More informationPhysics 1030 General Physics II
Final Exam April 20 6:00-9:00 pm University Center, Rm 210-224 (seats 1-211) 2016-03-30 Phys 1030 General Physics II (Gericke) 1 The De Broglie Wavelength (Section 29.5) de Broglie wavelength: hp Wavelength
More informationEarly Quantum Theory and Models of the Atom
Early Quantum Theory and Models of the Atom Electron Discharge tube (circa 1900 s) There is something ( cathode rays ) which is emitted by the cathode and causes glowing Unlike light, these rays are deflected
More informationChapter 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 informationRUTHERFORD ATOM E. Rutherford discovered that the atom had a hard core we call the nucleus.
CHAPTER 4- PARTICLE/WAVE NATURE OF MATTER RUTHERFORD ATOM E. Rutherford discovered that the atom had a hard core we call the nucleus. He scattered alpha particles ( 4 He 2 ) on a gold foil and noticed
More informationStates of Matter. Dates to Remember. Evaporation. Why does it get warmer when it begins to snow? Do you understand this graph?
Dates to Remember States of Matter Next test runs Tues. through Thurs. Vocab quiz available now. (a) Gas (b) Liquid (c) Solid Which state of matter is associated with the most electrical potential? 1 animation
More informationRhonda Alexander IC Science Robert E. Lee
Rhonda Alexander IC Science Robert E. Lee Atom The smallest particle of an element that retains all of the chemical properties of the element. The Theory & Evidence for John Dalton s Atomic Theory: Around
More informationParticle Detectors and Quantum Physics (2) Stefan Westerhoff Columbia University NYSPT Summer Institute 2002
Particle Detectors and Quantum Physics (2) Stefan Westerhoff Columbia University NYSPT Summer Institute 2002 More Quantum Physics We know now how to detect light (or photons) One possibility to detect
More informationWe now realize that the phenomena of chemical interactions, and, ultimately life itself, are to be understood in terms of electromagnetism".
We now realize that the phenomena of chemical interactions, and, ultimately life itself, are to be understood in terms of electromagnetism". -Richard Feynman Quantum H Atom Review Radia Wave Function (1s):
More informationAtom and Quantum. Atomic Nucleus 11/3/2008. Atomic Spectra
Atom and Quantum Atomic Nucleus Ernest Rutherford 1871-1937 Rutherford s Gold Foil Experiment Deflection of alpha particles showed the atom to be mostly empty space with a concentration of mass at its
More informationQuantum 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 informationUNIT : QUANTUM THEORY AND THE ATOM
Name St.No. Date(YY/MM/DD) / / Section UNIT 102-10: QUANTUM THEORY AND THE ATOM OBJECTIVES Atomic Spectra for Hydrogen, Mercury and Neon. 1. To observe various atomic spectra with a diffraction grating
More informationChapter 31 Atomic Physics
100 92 86 100 92 84 100 92 84 98 92 83 97 92 82 96 91 80 96 91 76 95 91 74 95 90 68 95 89 67 95 89 66 94 87 93 86 No. of Students in Range Exam 3 Score Distribution 25 22 20 15 10 10 5 3 2 0 0 0 0 0 0
More informationChapter 27 Early Quantum Theory and Models of the Atom
Chapter 27 Early Quantum Theory and Models of the Atom Modern Physics 19th century physics had so many great successes, that most people felt nature was almost fully understood. Just a few small clouds
More informationPSI 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 informationAtomic Structure ATOMIC STRUCTURE. All matter is composed of atoms.
All matter is composed of atoms. ATOMIC STRUCTURE Understanding the structure of atoms is critical to understanding the properties of matter HISTORY OF THE ATOM DALTONS ATOMIC THEORY 1808 John Dalton suggested
More informationDemocritus & Leucippus (~400 BC) Greek philosophers: first to propose that matter is made up of particles called atomos, the Greek word for atoms
Chemistry Ms. Ye Name Date Block The Evolution of the Atomic Model Since atoms are too small to see even with a very powerful microscope, scientists rely upon indirect evidence and models to help them
More informationNuclear Chemistry. Atomic Structure Notes Start on Slide 20 from the second class lecture
Nuclear Chemistry Atomic Structure Notes Start on Slide 20 from the second class lecture The Birth of an Idea Democritus, 400 B.C. coined the term atom If you divide matter into smaller and smaller pieces,
More information1/l = R(1/n' 2-1/n 2 ) n > n', both integers R = nm -1
Worksheet 14 Bohr Model of the Hydrogen Atom In the late 1800's, Johannes Rydberg, building on the work of Johann Balmer, had come up with a mathematical formula that could be used to find the wavelengths
More informationPhysics 30 Modern Physics Unit: Atomic Basics
Physics 30 Modern Physics Unit: Atomic Basics Models of the Atom The Greeks believed that if you kept dividing matter into smaller and smaller pieces, you would eventually come to a bit of matter that
More informationCONCEPT MAP ATOMS. Atoms. 1.Thomson model 2.Rutherford model 3.Bohr model. 6. Hydrogen spectrum
CONCEPT MAP ATOMS Atoms 1.Thomson model 2.Rutherford model 3.Bohr model 4.Emission line spectra 2a. Alpha scattering experiment 3a. Bohr s postulates 6. Hydrogen spectrum 8. De Broglie s explanation 5.Absorption
More informationChapter 7: The Quantum-Mechanical Model of the Atom
C h e m i s t r y 1 A : C h a p t e r 7 P a g e 1 Chapter 7: The Quantum-Mechanical Model of the Atom Homework: Read Chapter 7. Work out sample/practice exercises Check for the MasteringChemistry.com assignment
More information12/04/2012. Models of the Atom. Quantum Physics versus Classical Physics The Thirty-Year War ( )
Quantum Physics versus Classical Physics The Thirty-Year War (1900-1930) Interactions between Matter and Radiation Models of the Atom Bohr s Model of the Atom Planck s Blackbody Radiation Models of the
More informationThe Atom. Describe a model of the atom that features a small nucleus surrounded by electrons.
The Atom Describe a model of the atom that features a small nucleus surrounded by electrons. A guy by the name of Bohr created a model for the atom that consisted of an small nucleus surrounded by orbiting
More informationPhysics 1C Lecture 29B
Physics 1C Lecture 29B Emission Spectra! The easiest gas to analyze is hydrogen gas.! Four prominent visible lines were observed, as well as several ultraviolet lines.! In 1885, Johann Balmer, found a
More informationPROGRESSION OF THE ATOMIC MODEL
PROGRESSION OF THE ATOMIC MODEL By 1808, it was widely accepted that matter was made up of ELEMENTS, which consisted of tiny PARTICLES called ATOMS. After 2000 years - DEMOCRITUS was right all along John
More informationChem 1075 Chapter 5 Models of the Atom Lecture Outline
Chem 1075 Chapter 5 Models of the Atom Lecture Outline Slide 2 Dalton Model of the Atom John Dalton proposed that is made up of The particles are or can be broken down into by chemical processes. cannot
More informationPHYS 3313 Section 001 Lecture #12
PHYS 3313 Section 001 Lecture #12 Monday, Feb. 24, 2014 Rutherford Scattering Experiment and Rutherford Atomic Model The Classic Atomic Model The Bohr Model of the Hydrogen Atom 1 Quiz 2 results Class
More informationThe Nucleus Came Next
The Nucleus Came Next Ernest Rutherford The New Zealand born British chemist and physicist who became known as the father of nuclear physics. He discovered the atomic nucleus, and thereby pioneered the
More informationHistorical 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 informationATOMIC MODELS. Models are formulated to fit the available data. Atom was known to have certain size. Atom was known to be neutral.
ATOMIC MODELS Models are formulated to fit the available data. 1900 Atom was known to have certain size. Atom was known to be neutral. Atom was known to give off electrons. THOMPSON MODEL To satisfy the
More informationChapter 44. Nuclear Structure
Chapter 44 Nuclear Structure Milestones in the Development of Nuclear Physics 1896: the birth of nuclear physics Becquerel discovered radioactivity in uranium compounds Rutherford showed the radiation
More information29:006 FINAL EXAM FRIDAY MAY 11 3:00 5:00 PM IN LR1 VAN
L 33 Modern Physics [1] 29:006 FINAL EXAM FRIDAY MAY 11 3:00 5:00 PM IN LR1 VAN Introduction- quantum physics Particles of light PHOTONS The photoelectric effect Photocells & intrusion detection devices
More informationThe Structure of the Atom
The Structure of the Atom Chapter 4 in Rex and Thornton s Modern Physics Wed. October 26, 2016 S 1 In this chapter... S We ll explore how our understanding of atomic structure developed S Ancient Greek
More information1. What is the minimum energy required to excite a mercury atom initially in the ground state? ev ev ev
Page 1 of 10 modern bank Name 25-MAY-05 1. What is the minimum energy required to excite a mercury atom initially in the ground state? 1. 4.64 ev 3. 10.20 ev 2. 5.74 ev 4. 10.38 ev 2. The diagram represents
More informationSurprise, surprise, surprise
Experiment Rutherford had two grad students, Marsden and Geiger. It was decided that Geiger would gain some practice by conducting a series of experiments with gold and alpha particles. The positively
More informationlike firing a 16 shell at a piece of tissue paper and seeing it bounce back. - E Rutherford
Black body radiation [const.] λ max = T E radiated surf. area Planck E f hf = T E W KE 4 ROY G BIV Einstein Photo-electric effect- Photons Thompson electron identification B + F v R +q 2 mv F= =qvb=f R
More informationSection 3.1 Substances Are Made of Atoms
Section 3.1 Substances Are Made of Atoms Objectives: 1. State the three laws that support the existence of atoms. 2. List the five principles of John Dalton s atomic theory. Vocabulary: law of definite
More informationModern Physics- Introduction. L 35 Modern Physics [1] ATOMS and classical physics. Newton s Laws have flaws! accelerated charges radiate energy
L 35 Modern Physics [1] Introduction- quantum physics Particles of light PHOTONS The photoelectric effect Photocells & intrusion detection devices The Bohr atom emission & absorption of radiation LASERS
More information