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1 | |
The concepts of a "particle" and a "wave" |
| | A) | are clear and completely distinct from one another in both classical and modern physics. |
| | B) | can both be applied to electromagnetic radiation. |
| | C) | have found little use in quantum physics. |
| | D) | all of the above are true. |
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2 | |
Concerning the photoelectric effect, which of the following is not true? |
| | A) | For most metals, ultraviolet light is needed for the photoelectric effect to occur. |
| | B) | Because a faint light contains very little energy, it take as few minutes before electrons are emitted from the metal it is shining upon. |
| | C) | A bright light causes more electrons to be emitted than a faint light. |
| | D) | Higher frequency light emits electrons with higher kinetic energies. |
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3 | |
Max Planck |
| | A) | proposed that light consists of photons. |
| | B) | developed a theory to explain the absorption of light by so-called black bodies. |
| | C) | suggested that to explain the spectrum emitted by a hot object, the energy could be viewed as given off in quanta, or units of energy. |
| | D) | linked the energy of a photon with its amplitude using Maxwell's equations. |
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4 | |
Photons |
| | A) | possess small but significant mass. |
| | B) | move at speeds proportional to their frequencies. |
| | C) | lack momentum. |
| | D) | are localized in small regions of space. |
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5 | |
Planck's constant |
| | A) | remains unknown to this day. |
| | B) | is the inverse of Einstein's constant. |
| | C) | is used to find the quantum energy associated with a certain frequency of light. |
| | D) | is not really constant since it varies from one part of the universe to another. |
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6 | |
X-rays |
| | A) | were first discovered in 1895 prior to Planck's concept of quanta. |
| | B) | demonstrate that phenomena of electron kinetic energy being transformed into photon energy. |
| | C) | are an extremely penetrating form of radiation. |
| | D) | all of the above are true. |
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7 | |
The wave theory of light and the quantum theory of light |
| | A) | are in direct contradiction to one another. |
| | B) | together show that X-rays really are an unknown (hence the "X") phenomenon. |
| | C) | complement each other. |
| | D) | are both necessary to explain the interference patterns of light. |
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8 | |
According to our best observations, light |
| | A) | is exclusively a wave phenomenon. |
| | B) | is exclusively a particle phenomenon. |
| | C) | in any particular event, exhibits either a wave nature or a particle nature, never both at the same time. |
| | D) | has neither wave nor particle properties. |
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9 | |
The de Broglie wavelength of an object |
| | A) | is equal to Planck's constant divided by the momentum of the object. |
| | B) | is significant only if the object is moving at 1% of the speed of light or faster. |
| | C) | cannot be determined accurately for any subatomic particles. |
| | D) | increases as the velocity of the particle increases. |
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10 | |
Matter waves |
| | A) | only make good common sense, as de Broglie demonstrated. |
| | B) | contradict the concept of photons as proposed by Einstein. |
| | C) | are always associated with particles and photons in any state. |
| | D) | are most significant at the atomic and subatomic level. |
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11 | |
The wave function (psi, y) |
| | A) | represents the particle function associated with a wave. |
| | B) | a large value of psi squared indicates the strong possibility of the particle's presence. |
| | C) | a small value of psi squared indicates the strong possibility of the particle's presence. |
| | D) | is unrelated to quantum theory and de Broglie waves. |
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12 | |
An important implication of the uncertainty principle discovered by Werner Heisenberg is |
| | A) | very small particles moving at slow speeds contain vast quantities of energy, the basis of the atomic bomb. |
| | B) | if we can gather enough data, then it may be possible to predict the future based on present boundary conditions. |
| | C) | above a certain particle size the de Broglie waves are so insignificant that they drop to zero. |
| | D) | we can never predict the future with absolute certainty because it is impossible to know the present with certainty. |
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13 | |
Emission spectra and absorption spectra |
| | A) | for a single element complement one another. |
| | B) | can be used to identify elements in unknown samples, but only if the element is already known by classical chemical means. |
| | C) | when combined together form a series of bright lines. |
| | D) | for certain pairs of closely-related elements are identical. |
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14 | |
When the sun's spectrum was first studied in detail |
| | A) | it was discovered that the sun's interior is cooler than the exterior. |
| | B) | very few elements are found in the sun, and all of them were well known from earth samples. |
| | C) | an apparently new element was discovered, subsequently named helium. |
| | D) | spectral series were found to be lacking in pure sunlight. |
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15 | |
According to the Bohr model of the atom |
| | A) | electrons in orbit around nuclei lose energy so slowly that the universe should exist for at least another five billion years. |
| | B) | quantum theory is not applicable to the ultra-structure of an atom. |
| | C) | electrons around a nucleus can have only certain particular energies and can only occupy certain specific orbits at particular distances from the nucleus. |
| | D) | all of the above are true. |
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16 | |
An electron can _____________ revolve in a stable orbit around an atomic nucleus while continuously radiating energy without moving to a smaller orbit. |
| | A) | often |
| | B) | sometimes is less than a de Broglie wavelength in circumference |
| | C) | never |
| | D) | the answer depends on whether or not the atom is radioactive |
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17 | |
An atom is said to be in an excited state when it has one or more electrons |
| | A) | at rest. |
| | B) | inside the nucleus. |
| | C) | in its lower energy level. |
| | D) | in a larger orbit than the smallest possible orbits. |
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18 | |
When an atom absorbs a photon, one of its orbital electrons |
| | A) | jumps from a higher to a lower energy level. |
| | B) | gains energy. |
| | C) | is absorbed by the nucleus. |
| | D) | turns into gamma radiation. |
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19 | |
An electron can circle a nucleus only in orbits that contain a whole number of de Broglie wavelengths. This statement |
| | A) | has a few exceptions, but they are not important at a quantum level. |
| | B) | implies that the quantum number, n, is the sum of all the orbits minus the length of the de Broglie wave. |
| | C) | combines both the particle and wave characters of the electron into a single statement. |
| | D) | suggests that the uncertainty principle is not correct after all. |
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20 | |
Which of the following types of radiation is emitted directly by the electronic structures of atoms? |
| | A) | beta radiation |
| | B) | visible light |
| | C) | alpha radiation |
| | D) | gamma rays |
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21 | |
In coherent light, |
| | A) | the light waves are emitted randomly. |
| | B) | the light waves are in step with one another. |
| | C) | the light is said to carry information. |
| | D) | many different frequencies interact with one another to form a multi-dimensional picture. |
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22 | |
Which of the following properties is a characteristic of the light waves from a laser? |
| | A) | The waves all have the same frequency |
| | B) | The waves are all in step with one another |
| | C) | The waves form a narrow beam |
| | D) | All of the above are true |
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23 | |
Comparing newtonian mechanics to quantum mechanics, |
| | A) | it is obvious that if one is true then the other must be absolutely false. |
| | B) | most scientists today believe that quantum mechanics was a false side track in physics. |
| | C) | quantum mechanics includes newtonian mechanics as a special case. |
| | D) | neither actually agrees with fact as we know it, although newtonian mechanics is a little closer. |
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24 | |
Of the four quantum numbers for an atomic electron |
| | A) | two determine the electron's mass. |
| | B) | two determine the electron's spin. |
| | C) | one determines the size and shape of the electron's orbit. |
| | D) | three determine the size and shape of the probability cloud of an electron. |
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25 | |
Wolfgang Pauli concluded that |
| | A) | in any single atom, no more than three electrons can occupy a particular orbit. |
| | B) | the quantum numbers for a particular electron in an atom can never be changed. |
| | C) | only one electron in an atom can exist in a given quantum state. |
| | D) | there is a unique set of quantum numbers for every single atom in the universe. |
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