Borh's Derivation of Balmer-Rydberg Formula Through Quantum Mechanics
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Quantum Theory of the Hydrogen Atom
Quantum Theory of the Hydrogen Atom Chemistry 35 Fall 2000 Balmer and the Hydrogen Spectrum n 1885: Johann Balmer, a Swiss schoolteacher, empirically deduced a formula which predicted the wavelengths of emission for Hydrogen: l (in Å) = 3645.6 x n2 for n = 3, 4, 5, 6 n2 -4 •Predicts the wavelengths of the 4 visible emission lines from Hydrogen (which are called the Balmer Series) •Implies that there is some underlying order in the atom that results in this deceptively simple equation. 2 1 The Bohr Atom n 1913: Niels Bohr uses quantum theory to explain the origin of the line spectrum of hydrogen 1. The electron in a hydrogen atom can exist only in discrete orbits 2. The orbits are circular paths about the nucleus at varying radii 3. Each orbit corresponds to a particular energy 4. Orbit energies increase with increasing radii 5. The lowest energy orbit is called the ground state 6. After absorbing energy, the e- jumps to a higher energy orbit (an excited state) 7. When the e- drops down to a lower energy orbit, the energy lost can be given off as a quantum of light 8. The energy of the photon emitted is equal to the difference in energies of the two orbits involved 3 Mohr Bohr n Mathematically, Bohr equated the two forces acting on the orbiting electron: coulombic attraction = centrifugal accelleration 2 2 2 -(Z/4peo)(e /r ) = m(v /r) n Rearranging and making the wild assumption: mvr = n(h/2p) n e- angular momentum can only have certain quantified values in whole multiples of h/2p 4 2 Hydrogen Energy Levels n Based on this model, Bohr arrived at a simple equation to calculate the electron energy levels in hydrogen: 2 En = -RH(1/n ) for n = 1, 2, 3, 4, . -
The Balmer Series
The Balmer Series Introduction Historically, the spectral lines of hydrogen have been categorized as six distinct series. The visible portion of the hydrogen spectrum is contained in the Balmer series, named after Johann Balmer who discovered an empirical relationship for calculating its wave- lengths [2]. In 1885 Balmer discovered that by labeling the four visible lines of the hydorgen spectrum with integers n, (n = 3, 4, 5, 6) (See Table 1 and Figure 1) each wavelength λ could be calculated from the relationship n2 λ = B , (1) n2 − 4 where B = 364.56 nm. Johannes Rydberg generalized Balmer’s result to include all of the wavelengths of the hydrogen spectrum. The Balmer formula is more commonly re–expressed in the form of the Rydberg formula 1 1 1 = RH − , (2) λ 22 n2 where n =3, 4, 5 . and the Rydberg constant RH =4/B. The purpose of this experiment is to determine the wavelengths of the visible spec- tral lines of hydrogen using a spectrometer and to calculate the Balmer constant B. Procedure The spectrometer used in this experiment is shown in Fig. 1. Adjust the diffraction grating so that the normal to its plane makes a small angle α to the incident beam of light. This is shown schematically in Fig. 2. Since α u 0, the angles between the first and zeroth order intensity maxima on either side, θ and θ0 respectively, are related to the wavelength λ of the incident light according to [1] λ = d sin(φ) , (3) accurate to first order in α. Here, d is the separation between the slits of the grating, and θ0 + θ φ = (4) 2 1 Color Wavelength [nm] Integer [n] Violet2 410.2 6 Violet1 434.0 5 blue 486.1 4 red 656.3 3 Table 1: The wavelengths and integer associations of the visible spectral lines of hy- drogen shown in Fig. -
Lecture #2: August 25, 2020 Goal Is to Define Electrons in Atoms
Lecture #2: August 25, 2020 Goal is to define electrons in atoms • Bohr Atom and Principal Energy Levels from “orbits”; Balance of electrostatic attraction and centripetal force: classical mechanics • Inability to account for emission lines => particle/wave description of atom and application of wave mechanics • Solutions of Schrodinger’s equation, Hψ = Eψ Required boundaries => quantum numbers (and the Pauli Exclusion Principle) • Electron configurations. C: 1s2 2s2 2p2 or [He]2s2 2p2 Na: 1s2 2s2 2p6 3s1 or [Ne] 3s1 => Na+: [Ne] Cl: 1s2 2s2 2p6 3s23p5 or [Ne]3s23p5 => Cl-: [Ne]3s23p6 or [Ar] What you already know: Quantum Numbers: n, l, ml , ms n is the principal quantum number, indicates the size of the orbital, has all positive integer values of 1 to ∞(infinity) (Bohr’s discrete orbits) l (angular momentum) orbital 0s l is the angular momentum quantum number, 1p represents the shape of the orbital, has integer values of (n – 1) to 0 2d 3f ml is the magnetic quantum number, represents the spatial direction of the orbital, can have integer values of -l to 0 to l Other terms: electron configuration, noble gas configuration, valence shell ms is the spin quantum number, has little physical meaning, can have values of either +1/2 or -1/2 Pauli Exclusion principle: no two electrons can have all four of the same quantum numbers in the same atom (Every electron has a unique set.) Hund’s Rule: when electrons are placed in a set of degenerate orbitals, the ground state has as many electrons as possible in different orbitals, and with parallel spin. -
Optical Properties of Bulk and Nano
Lecture 3: Optical Properties of Bulk and Nano 5 nm Course Info First H/W#1 is due Sept. 10 The Previous Lecture Origin frequency dependence of χ in real materials • Lorentz model (harmonic oscillator model) e- n(ω) n' n'' n'1= ω0 + Nucleus ω0 ω Today optical properties of materials • Insulators (Lattice absorption, color centers…) • Semiconductors (Energy bands, Urbach tail, excitons …) • Metals (Response due to bound and free electrons, plasma oscillations.. ) Optical properties of molecules, nanoparticles, and microparticles Classification Matter: Insulators, Semiconductors, Metals Bonds and bands • One atom, e.g. H. Schrödinger equation: E H+ • Two atoms: bond formation ? H+ +H Every electron contributes one state • Equilibrium distance d (after reaction) Classification Matter ~ 1 eV • Pauli principle: Only 2 electrons in the same electronic state (one spin & one spin ) Classification Matter Atoms with many electrons Empty outer orbitals Outermost electrons interact Form bands Partly filled valence orbitals Filled Energy Inner Electrons in inner shells do not interact shells Do not form bands Distance between atoms Classification Matter Insulators, semiconductors, and metals • Classification based on bandstructure Dispersion and Absorption in Insulators Electronic transitions No transitions Atomic vibrations Refractive Index Various Materials 3.4 3.0 2.0 Refractive index: n’ index: Refractive 1.0 0.1 1.0 10 λ (µm) Color Centers • Insulators with a large EGAP should not show absorption…..or ? • Ion beam irradiation or x-ray exposure result in beautiful colors! • Due to formation of color (absorption) centers….(Homework assignment) Absorption Processes in Semiconductors Absorption spectrum of a typical semiconductor E EC Phonon Photon EV ωPhonon Excitons: Electron and Hole Bound by Coulomb Analogy with H-atom • Electron orbit around a hole is similar to the electron orbit around a H-core • 1913 Niels Bohr: Electron restricted to well-defined orbits n = 1 + -13.6 eV n = 2 n = 3 -3.4 eV -1.51 eV me4 13.6 • Binding energy electron: =−=−=e EB 2 2 eV, n 1,2,3,.. -
Rydberg Constant and Emission Spectra of Gases
Page 1 of 10 Rydberg constant and emission spectra of gases ONE WEIGHT RECOMMENDED READINGS 1. R. Harris. Modern Physics, 2nd Ed. (2008). Sections 4.6, 7.3, 8.9. 2. Atomic Spectra line database https://physics.nist.gov/PhysRefData/ASD/lines_form.html OBJECTIVE - Calibrating a prism spectrometer to convert the scale readings in wavelengths of the emission spectral lines. - Identifying an "unknown" gas by measuring its spectral lines wavelengths. - Calculating the Rydberg constant RH. - Finding a separation of spectral lines in the yellow doublet of the sodium lamp spectrum. INSTRUCTOR’S EXPECTATIONS In the lab report it is expected to find the following parts: - Brief overview of the Bohr’s theory of hydrogen atom and main restrictions on its application. - Description of the setup including its main parts and their functions. - Description of the experiment procedure. - Table with readings of the vernier scale of the spectrometer and corresponding wavelengths of spectral lines of hydrogen and helium. - Calibration line for the function “wavelength vs reading” with explanation of the fitting procedure and values of the parameters of the fit with their uncertainties. - Calculated Rydberg constant with its uncertainty. - Description of the procedure of identification of the unknown gas and statement about the gas. - Calculating resolution of the spectrometer with the yellow doublet of sodium spectrum. INTRODUCTION In this experiment, linear emission spectra of discharge tubes are studied. The discharge tube is an evacuated glass tube filled with a gas or a vapor. There are two conductors – anode and cathode - soldered in the ends of the tube and connected to a high-voltage power source outside the tube. -
Bohr Model of Hydrogen
Chapter 3 Bohr model of hydrogen Figure 3.1: Democritus The atomic theory of matter has a long history, in some ways all the way back to the ancient Greeks (Democritus - ca. 400 BCE - suggested that all things are composed of indivisible \atoms"). From what we can observe, atoms have certain properties and behaviors, which can be summarized as follows: Atoms are small, with diameters on the order of 0:1 nm. Atoms are stable, they do not spontaneously break apart into smaller pieces or collapse. Atoms contain negatively charged electrons, but are electrically neutral. Atoms emit and absorb electromagnetic radiation. Any successful model of atoms must be capable of describing these observed properties. 1 (a) Isaac Newton (b) Joseph von Fraunhofer (c) Gustav Robert Kirch- hoff 3.1 Atomic spectra Even though the spectral nature of light is present in a rainbow, it was not until 1666 that Isaac Newton showed that white light from the sun is com- posed of a continuum of colors (frequencies). Newton introduced the term \spectrum" to describe this phenomenon. His method to measure the spec- trum of light consisted of a small aperture to define a point source of light, a lens to collimate this into a beam of light, a glass spectrum to disperse the colors and a screen on which to observe the resulting spectrum. This is indeed quite close to a modern spectrometer! Newton's analysis was the beginning of the science of spectroscopy (the study of the frequency distri- bution of light from different sources). The first observation of the discrete nature of emission and absorption from atomic systems was made by Joseph Fraunhofer in 1814. -
Particle Nature of Matter
Solved Problems on the Particle Nature of Matter Charles Asman, Adam Monahan and Malcolm McMillan Department of Physics and Astronomy University of British Columbia, Vancouver, British Columbia, Canada Fall 1999; revised 2011 by Malcolm McMillan Given here are solutions to 5 problems on the particle nature of matter. The solutions were used as a learning-tool for students in the introductory undergraduate course Physics 200 Relativity and Quanta given by Malcolm McMillan at UBC during the 1998 and 1999 Winter Sessions. The solutions were prepared in collaboration with Charles Asman and Adam Monaham who were graduate students in the Department of Physics at the time. The problems are from Chapter 3 The Particle Nature of Matter of the course text Modern Physics by Raymond A. Serway, Clement J. Moses and Curt A. Moyer, Saunders College Publishing, 2nd ed., (1997). Coulomb's Constant and the Elementary Charge When solving numerical problems on the particle nature of matter it is useful to note that the product of Coulomb's constant k = 8:9876 × 109 m2= C2 (1) and the square of the elementary charge e = 1:6022 × 10−19 C (2) is ke2 = 1:4400 eV nm = 1:4400 keV pm = 1:4400 MeV fm (3) where eV = 1:6022 × 10−19 J (4) Breakdown of the Rutherford Scattering Formula: Radius of a Nucleus Problem 3.9, page 39 It is observed that α particles with kinetic energies of 13.9 MeV or higher, incident on copper foils, do not obey Rutherford's (sin φ/2)−4 scattering formula. • Use this observation to estimate the radius of the nucleus of a copper atom. -
Toward Quantum Simulation with Rydberg Atoms Thanh Long Nguyen
Study of dipole-dipole interaction between Rydberg atoms : toward quantum simulation with Rydberg atoms Thanh Long Nguyen To cite this version: Thanh Long Nguyen. Study of dipole-dipole interaction between Rydberg atoms : toward quantum simulation with Rydberg atoms. Physics [physics]. Université Pierre et Marie Curie - Paris VI, 2016. English. NNT : 2016PA066695. tel-01609840 HAL Id: tel-01609840 https://tel.archives-ouvertes.fr/tel-01609840 Submitted on 4 Oct 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. DÉPARTEMENT DE PHYSIQUE DE L’ÉCOLE NORMALE SUPÉRIEURE LABORATOIRE KASTLER BROSSEL THÈSE DE DOCTORAT DE L’UNIVERSITÉ PIERRE ET MARIE CURIE Spécialité : PHYSIQUE QUANTIQUE Study of dipole-dipole interaction between Rydberg atoms Toward quantum simulation with Rydberg atoms présentée par Thanh Long NGUYEN pour obtenir le grade de DOCTEUR DE L’UNIVERSITÉ PIERRE ET MARIE CURIE Soutenue le 18/11/2016 devant le jury composé de : Dr. Michel BRUNE Directeur de thèse Dr. Thierry LAHAYE Rapporteur Pr. Shannon WHITLOCK Rapporteur Dr. Bruno LABURTHE-TOLRA Examinateur Pr. Jonathan HOME Examinateur Pr. Agnès MAITRE Examinateur To my parents and my brother To my wife and my daughter ii Acknowledgement “Voici mon secret. -
Improving the Accuracy of the Numerical Values of the Estimates Some Fundamental Physical Constants
Improving the accuracy of the numerical values of the estimates some fundamental physical constants. Valery Timkov, Serg Timkov, Vladimir Zhukov, Konstantin Afanasiev To cite this version: Valery Timkov, Serg Timkov, Vladimir Zhukov, Konstantin Afanasiev. Improving the accuracy of the numerical values of the estimates some fundamental physical constants.. Digital Technologies, Odessa National Academy of Telecommunications, 2019, 25, pp.23 - 39. hal-02117148 HAL Id: hal-02117148 https://hal.archives-ouvertes.fr/hal-02117148 Submitted on 2 May 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Improving the accuracy of the numerical values of the estimates some fundamental physical constants. Valery F. Timkov1*, Serg V. Timkov2, Vladimir A. Zhukov2, Konstantin E. Afanasiev2 1Institute of Telecommunications and Global Geoinformation Space of the National Academy of Sciences of Ukraine, Senior Researcher, Ukraine. 2Research and Production Enterprise «TZHK», Researcher, Ukraine. *Email: [email protected] The list of designations in the text: l -
The Hydrogen Atom (Finite Difference Equation/Discrete Wave Vectors/Bohr-Rydberg Formula) FREDERICK T
Proc. Natl. Acad. Sci. USA Vol. 83, pp. 5753-5755, August 1986 Chemistry Discrete wave mechanics: The hydrogen atom (finite difference equation/discrete wave vectors/Bohr-Rydberg formula) FREDERICK T. WALL Department of Chemistry, B-017, University of California at San Diego, La Jolla, CA 92093 Contributed by Frederick T. Wall, March 31, 1986 ABSTRACT The quantum mechanical problem of the hy- its wave vector energy counterpart.* If V is small compared drogen atom is treated by use of a finite difference equation in to mc2, then V and l9 are substantially the same, but for large place of Schrodinger's differential equation. The exact solu- negative values of V, the two can be significantly different. tion leads to a wave vector energy expression that is readily The next question to be answered is how the potential en- converted to the Bohr-Rydberg formula. (The calculations ergy is introduced into the finite difference equation. In our here reported are limited to spherically symmetric states.) The problem, we shall write that wave vectors reduce to the familiar solutions of Schrodinger's equation as c -- w. The internal consistency and limiting be- O(r - A) - 2(X + V/mc2)4(r) + /(r + A) = 0, [2] havior provide support for the view that the equations em- ployed could well constitute an approach to a relativistic for- with mulation of wave mechanics. X = = (1 - 26/E)"2 [3] In an earlier paper (1), I set forth a simple difference equa- EI/E tion for the wave mechanical description of a free particle. This was accompanied by a postulatory basis for interpreting where & is the wave vector energy, and certain parameters related to the energy, thus appearing to provide a possible connection to relativity. -
Note to 8.13 Students
Note to 8.13 students: Feel free to look at this paper for some suggestions about the lab, but please reference/acknowledge me as if you had read my report or spoken to me in person. Also note that this is only one way to do the lab and data analysis, and there are nearly an infinite number of other things to do that would be better. I made some mistakes doing this lab. Here are a couple I found (and some more tips): Use a smaller step and get more precise data than what we had. Then fit • a curve, don’t just pick out a peak. The Hg calibration is actually something like a sin wave instead of a cubic. • Also don’t follow the old version of Melissionos word for word. They use an optical system with a prism oppose to a diffraction grating. We took data strategically so we could use unweighted fits • The mystery tube was actually N, whoops my bad. We later found a • drawer full of tubes and compared the colors. It was obviously N. Again whoops, it was our first experiment okay?! 1 Optical Spectroscopy Rachel Bowens-Rubin∗ MIT Department of Physics (Dated: July 12, 2010) The spectra of mercury, hydrogen, deuterium, sodium, and an unidentified mystery tube were measured using a monochromator to determine diffrent properties of their spectra. The spectrum of mercury was used to calibrate for error due to optics in the monochronomator. The measurements of the Balmer series lines were used to determine the Rydberg constants for hydrogen and deuterium, 7 7 1 7 7 1 Rh =1.0966 10 0.0002 10 m− and Rd=1.0970 10 0.0003 10 m− . -
Rydberg Excitation of Single Atoms for Applications in Quantum Information and Metrology Aaron Hankin
University of New Mexico UNM Digital Repository Physics & Astronomy ETDs Electronic Theses and Dissertations 1-28-2015 Rydberg Excitation of Single Atoms for Applications in Quantum Information and Metrology Aaron Hankin Follow this and additional works at: https://digitalrepository.unm.edu/phyc_etds Recommended Citation Hankin, Aaron. "Rydberg Excitation of Single Atoms for Applications in Quantum Information and Metrology." (2015). https://digitalrepository.unm.edu/phyc_etds/23 This Dissertation is brought to you for free and open access by the Electronic Theses and Dissertations at UNM Digital Repository. It has been accepted for inclusion in Physics & Astronomy ETDs by an authorized administrator of UNM Digital Repository. For more information, please contact [email protected]. Aaron Hankin Candidate Physics and Astronomy Department This dissertation is approved, and it is acceptable in quality and form for publication: Approved by the Dissertation Committee: Ivan Deutsch , Chairperson Carlton Caves Keith Lidke Grant Biedermann Rydberg Excitation of Single Atoms for Applications in Quantum Information and Metrology by Aaron Michael Hankin B.A., Physics, North Central College, 2007 M.S., Physics, Central Michigan Univeristy, 2009 DISSERATION Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Physics The University of New Mexico Albuquerque, New Mexico December 2014 iii c 2014, Aaron Michael Hankin iv Dedication To Maiko and our unborn daughter. \There are wonders enough out there without our inventing any." { Carl Sagan v Acknowledgments The experiment detailed in this manuscript evolved rapidly from an empty lab nearly four years ago to its current state. Needless to say, this is not something a graduate student could have accomplished so quickly by him or herself.