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 frequency as defined for sound, radio, and light waves. C) a special characteristic of quantum phenomena. D) none of these 2) The ratio of the energy of a photon to its frequency is 2) A) Planck's constant. B) the photon's wavelength. C) pi. D) the photon's speed. E) not known. 3) Which has less energy per photon? 3) A) red light B) blue light C) Both have the same energy. 4) The photoelectric effect best demonstrates the 4) A) particle nature of light. B) wave nature of light. C) both of these D) none of these 5) Quantum uncertainties are most predominant for simultaneously measuring the speed and location of A) an electron. B) a spitball. C) a baseball. 5) 6) A quantum of light is called a(n) 6) A) proton. B) electron. C) notron. D) neutron. 7) In the photoelectric effect, the brighter the illuminating light on a photosensitive surface, the greater the A) number of ejected electrons. B) velocity of ejected electrons. 7) 8) In the photoelectric effect, the greater the frequency of the illuminating light, the greater the 8) A) number of ejected electrons. B) maximum velocity of ejected electrons. 9) Light behaves primarily as a wave when it 9) A) travels from one place to another. B) interacts with matter. 10) Two photons have the same wavelength. They also have the same 10) A) frequency. B) energy. 1
11) Light behaves primarily as a particle when it 11) A) travels from one place to another. B) interacts with matter. 12) In the double-slit experiment with electrons, the electrons arrive at the screen in a 12) A) wave-like way with a pattern that is wave-like. B) particle-like way with a pattern that is particle-like. C) particle-like way with a pattern that is wave-like. D) wave-like way with a pattern that is particle-like. 13) The uncertainty principle applies not only to momentum and position, but also to energy and time. This statement is A) false. B) true. 14) According to the uncertainty principle, the more we know about a particle's momentum, the less we know about its A) mass. B) kinetic energy. C) location. D) speed. 13) 14) 15) According to quantum physics, looking at a star through a telescope 15) A) has no effect on the processes occurring in the star. B) affects the processes occurring in the star. 16) In the relationship E = hf for a photon emitted from an atom, the symbol E is used to represent the energy A) of the emitted photon. B) difference between atomic energy states producing the photon. C) both of these D) neither of these 17) A photosensitive surface is illuminated with both blue and violet light. The light that will cause the most electrons to be ejected is the A) blue light. B) violet light. C) Both eject the same number. D) not enough information given 16) 17) 18) Which of the following is not quantized? 18) A) energy B) electric charge C) radiation D) number of people in a room E) All are quantized. 19) An electron and a baseball move at the same speed. Which has the longer wavelength? 19) A) the electron B) the baseball C) Both have the same wavelength. 2
20) If a proton and an electron have identical momenta, the longer wavelength belongs to the 20) A) electron. B) proton. C) both the same 21) An electron and a proton are traveling at the same speed. Which has the longer wavelength? 21) A) the proton B) the electron C) Both have the same wavelength. 22) According to the uncertainty principle, the more we know about a particle's position, the less we know about its A) momentum. B) speed. C) kinetic energy. 23) According to quantum physics, measuring the velocity of a tiny charged particle with an electromagnet A) has no effect on the velocity of the particle. B) affects the velocity of the particle. 24) According to quantum physics, measuring the temperature of lava from a distant volcano by photographing its color with a telescopic camera A) has no effect on the temperature of the lava. B) affects the temperature of the lava. 25) A radiation detector measures the radioactivity of a piece of radium by catching and counting alpha particles it emits. According to quantum physics, making this measurement affects the A) radiation rate of the piece of radium. B) alpha particles that are caught. 22) 23) 24) 25) 26) Which of the following are conserved when a photon collides with an electron? 26) A) momentum, energy, and velocity B) momentum and velocity C) momentum and energy D) energy and velocity E) None of the above choices are correct. 27) Which of the following forms an interference pattern when directed toward two suitably spaced slits? A) light B) electrons C) sound 27) 3
28) According to the correspondence principle, a new theory is valid if it 28) A) accounts for confirmed results from the old theory. B) overlaps and agrees where the old theory works. C) predicts the same correct results as the old theory. 29) Quantization of electron energy states in an atom is better understood in terms of the electron's 29) A) particle nature. B) wave nature. C) neither of these 30) An excited hydrogen atom is capable of emitting radiation of 30) A) 3 frequencies. B) a single frequency. C) many more than 3 frequencies. 31) A beam of electrons has 31) A) particle properties. B) wave properties. 32) In the Bohr model of hydrogen, discrete radii and energy states result when an electron circles the atom in an integral number of A) wave frequencies. B) diffraction patterns. C) de Broglie wavelengths. D) none of these 32) 33) The Bohr model of the atom is akin to a 33) A) central heavy ball with lighter balls connected by springs. B) miniature solar system. C) blob of plum pudding, where raisins represent atomic nuclei. 34) We now consider the Bohr model of the atom to be 34) A) totally useless of historical interest only. B) an accurate picture of a hydrogen atom. C) defective and oversimplified, but still useful. 35) Orbital electrons do not spiral into the nucleus because of 35) A) the wave nature of the electron. B) angular momentum conservation. C) the large nuclear size compared to the electron's size. D) electromagnetic forces. 36) The main reason electrons occupy discrete orbits in an atom is because 36) A) electrons are basically discrete particles. B) the circumference of each orbit is an integral multiple of electron wavelengths. C) energy levels are quantized. D) electric forces act over quantized distances. 4
37) The correspondence principle applies to 37) A) all good theories. B) theories of submicroscopic phenomena. C) theories of macroscopic phenomena. 38) What do electrons have that protons always have in equal magnitude? 38) A) charge B) energy C) mass 39) The electrical force between an inner electron and the nucleus of an atom is larger for atoms of 39) A) the same for both B) low atomic number. C) high atomic number. 40) Two photons are emitted as an electron de-excites from the third quantum level to the second, and then to the ground state. The sum of the frequencies of the two photons equals the frequency of the single photon that would be emitted if the de-excitation were from the third to the ground state directly. This is according to A) the debroglie wavelength B) energy conservation. C) neither of these 41) An excited atom decays to its ground state and emits a photon of green light. If instead the atom decays to an intermediate state, then the light emitted could be A) violet. B) red. C) blue. D) any of these 40) 41) 42) Compared to the wavelengths of visible light, the wavelengths of matter waves are relatively 42) A) small. B) large. 43) A hypothetical atom has four distinct energy states. Assuming all transitions are possible, how many spectral lines can this atom produce? A) 5 B) more than 8 C) 8 D) 7 E) 6 43) 5
MATCHING. Choose the item in column 2 that best matches each item in column 1. 44) The emission of electrons from a metal surface when light shines upon it. 45) An elemental unit of a quantity, a discrete amount of something. 46) A fundamental constant that relates the energy of light quanta to their frequency. 47) Sets a limit on the accuracy of measurement for sub-atomic particles. 48) Any new theory must produce the same results as the old theory where the old theory is known to be valid. 49) The energy of an emitted photon is directly proportional to this. A) Planck's Constant B) Observation C) Correspondence Principle D) Frequency E) Photoelectric Effect F) Probing G) Standing Waves H) Uncertainty Principle I) Quantum 44) 45) 46) 47) 48) 49) 50) Looking at a cup of steaming coffee from across the room. 50) 51) Measuring a hot cup of coffee by immersing a thermometer. 51) 52) Electron orbital shells can be thought of as these. 52) SOLVE. Please show all work. Use a separate sheet of paper if necessary. 53) Calculate the debroglie wavelength of an electron (mass 9.11 x 10-31 kg) traveling at 3% the speed of light. 6