Slide 4 / 43 3 What is the difference between cathode rays and - - PDF document

AP Physics 2

Quantum Physics and Atomic Models

Multiple Choice www.njctl.org

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1 The “Cathode Ray Tube” experiment is associated with: A J.J. Tomson B J.S. Townsend C M. Plank D A.H.Compton

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2 The electron charge was measured the first time in: A Cathode ray experiment B Photoelectric effect experiment C Oil drop experiment D Compton effect experiment

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3 What is the difference between cathode rays and X-rays? A Both rays are made up of particles B Both rays are different types of electromagnetic radiation C Cathode rays are particles and X-rays are electromagnetic radiation D Cathode rays are electromagnetic radiation and X-rays are particles

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4 What distinctive phenomena are illustrated in X-ray spectra? (Select 2 answers) A Bremsstrahlung - deceleration of the electrons striking the anode B Acceleration of the electrons after they strike the anode C Internal atomic structure of the anode D Cathode ray penetration power

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5 Which of the following colors indicates an object of the lowest temperature? A Violet B Blue C Yellow D Red

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6 Which is a property of a black body radiator? A It absorbs all incident radiation, then re-emits it at a frequencies determined by its temperature. B It is always black, even when heated to high temperatures. C It absorbs all incident radiation and does not re-emit any radiation D As it is heated, it changes color from black to blue to red

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7 Which of the following photons has the greatest energy? A Infrared B Blue C γ- photon D ultraviolet-photon

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8 What discrepancy between experiment and theory helped lead Max Planck to his quantum theory? A The discovery of Cathode Rays B The discovery of X-Rays C The Ultraviolet Catastrophe D The discovery of electrons

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9 The energy of a photon depends on: A Amplitude B Speed C Temperature D Frequency

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10 How does the energy of a photon change if the wavelength is doubled? A Energy doubles B Energy quadruples C Energy stays the same D Energy is halved

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11 How does the momentum of a photon change if the wavelength is halved? A Doubles B Quadruples C Stays the same D Is cut to one-half

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12 The photoelectric effect explains: A The wave nature of light B The particle nature of light C The wave properties of an electron D The atomic structure

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13 The kinetic energy of photo-electrons depends on (Select 2 answers): A Angle of illumination B Intensity of light C Work function D Wavelength of light

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14 Which of the following is the formula of the photon momentum? A p = hf/c B p = cλ/h C p = hc/f D p = E/mc

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15 The stopping potential of photo-electrons depends on which of the following… (Select 2 answers) A The light intensity B The frequency of the photons C The composition of the metal surface D The speed of the incoming photons

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16 Which of the following formulas expresses the photoelectric effect? A hλ = W0 + KE B hf = W0 - KE C hf = W0 + KE D hλ = -W0 + KE

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17 Which of the following graphs correctly relates the maximum kinetic energy of photo-electrons and the frequency of the incident light? A B C D

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18 Which of the following graphs correctly relates the maximum kinetic energy of photo-electrons and the intensity of the incident light? A B C D

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19 Which of the following graphs correctly relates the de Broglie wavelength and the linear momentum of a particle? A B C D

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20 All of the following are properties of γ-rays EXCEPT: A They discharge electrified objects B They ionize gases C They are deflected by magnetic fields D They penetrate objects

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21 Which of the following phenomena provides the best evidence that light can have particle properties? A Diffraction of light B Compton scattering C Electron diffraction D γ-ray diffraction

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22 Which of the following phenomena provides the best evidence that particles can have wave properties? A The absorption of photons by electrons in an atom B The interference pattern produced by neutrons incident on a crystal C The production of x-rays by electrons striking a metal target D Compton scattering

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23 Which of the following formulas can be used to determine the de Broglie wavelength? A λ = hmv B λ = h/mv C λ = mv/h D λ = mc/h

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24 A photon can disappear producing an electron and positron. What is this phenomenon called? A X-Rays diffraction B Electron scattering C Annihilation D Pair production

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25 When a proton collides with an antiproton they disappear producing photons. This phenomenon is called… A X-Rays diffraction B Electron scattering C Annihilation D Pair production

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26 The following statement: “In order to understand a given experiment, we must use either the wave or particle theory, but not both” is called? A Wave theory of light B Particle theory of light C Principle of complementarity D Wave theory of matter

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27 Electrons are accelerated to a maximum speed of v in an X-Ray tube by an applied voltage V0. What is the maximum speed of the electrons if the voltage is quadrupled? A 4 v B 2 v C √(2)v D v/4

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28 In a Compton Effect experiment a photon scattered from an electron at rest increases its wavelength. Which of the following deflection angles θ provides the greatest increase in the wavelength of the scattered photon? A 0ο B 60ο C 90ο D 180ο

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29 If all of the following objects move at the same speed, which one will have the greatest deBroglie wavelength? A Neutron B Electron C Bowling ball D α- Particle

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30 Rutherford’s “Scattering α-particles by a gold foil” experiment disproved which of the following: A Plum-pudding model of the atom B Planetary model of the atom C De Broglie hypothesis D Wave nature of light

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31 In Rutherford’s experiment, most of α - particles pass through the foil without deflection. Which of the following properties of the atom can be explained by this observation? (Select 2 answers) A An atom’s positive charge is concentrated in the nucleus B The nucleus is made up neutrons and protons C Electrons move around the nucleus in orbits of quantized energy and angular momentum D An atom is mostly empty space

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32 Which of the following statement(s) can be associated with Bohr’s theory of the atom? (Select 2 answers) A An electron orbiting the nucleus can change its energy continuously B An electron orbiting the nucleus emits energy and falls on the nucleus C An electron can change its energy only by a certain portion when it jumps between the orbits D The angular momentum of an electron around the nucleus is equal an integer times h/2π

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33 When an electron falls from an orbit the first excited state (n=2) to the ground state (n=1): A A photon is emitted B A photon is absorbed C No photons are involved D An electron is emitted

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34 In the Bohr model, when an electron jumps from the n = 1 orbit (of radius r1) to the n = 3 orbit, what is its new orbital radius as a proportion of r1? A r1/9 B r1/3 C 3 r1 D 9 r1

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35 In the Bohr model, when an electron jumps from the n = 1 orbit (of energy E1) to the n = 4 orbit, what is its new energy as a proportion

• f E1?

A E1/9 B E1/16 C 4 E1 D 16 E1

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36 In the Bohr model, when an electron orbits a single proton in the n = 5 state, how many deBroglie wavelengths fit onto the circumference of this orbit? A 3 B 4 C 5 D 6

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37 An electron accelerated from rest by a 600V potential difference has a De Broglie wavelength of λ. What would the electron’s De Broglie wavelength be if the potential difference had been 150 V? A 2 λ B λ /2 C λ /4 D 4 λ

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38 According to Maxwell’s theory of electromagnetism, an electron

• rbiting a nucleus must:

A Change its energy in quantized amounts B Conserve its angular momentum C Conserve its energy D Radiate its energy

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39 A hypothetical atom has energy levels as shown by the graph (right). An electron is excited from the ground state to the -1 eV energy level. Which of the following are the energies of the emitted photons? (Select 2 answers) A 2 eV B 4 eV C 10 eV D 11 eV

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40 A container is filled with a gas consisting of atoms in the ground

• state. The energy energy level diagram for the atoms is shown on

the right. The gas is irradiated with electromagnetic radiation with the energy range from 4 eV to 9 eV. Which set of photon energies might be found in the emission spectrum A 1 eV, 2 eV, and 6 eV B 2 eV, 3 eV, and 4 eV C 1 eV, 3 eV, and 5 eV D 7 eV, 8 eV, and 9 eV

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41 A container is filled with a gas consisting of atoms in the ground

• state. The energy energy level diagram for the atoms is shown on

the right. The gas is irradiated with electro-magnetic radiation with the energy range from 4 eV to 9 eV. Which of the following transitions will produce a photon with the longest wavelength? A From n = 4 to n = 1 B From n = 2 to n = 1 C From n = 3 to n = 1 D From n = 4 to n = 3

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42 According to the Bohr’s theory of the hydrogen atom, electrons starting in the 4th energy level and eventually ending in the ground state could produce a total of how many different spectral lines? A 3 B 4 C 6 D 9

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