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1 | | According to the modern definition, which of the following is an element? |
| | A) | water |
| | B) | iron |
| | C) | air |
| | D) | All of the above. |
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2 | | John Dalton reasoned that atoms exist from the evidence that |
| | A) | elements could not be broken down into anything simpler. |
| | B) | water pours and flows when in the liquid state. |
| | C) | elements always combined in certain fixed ratios. |
| | D) | peanut butter and jelly could be combined in any ratio. |
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3 | | The electron was discovered through experiments with |
| | A) | radioactivity. |
| | B) | light. |
| | C) | matter waves. |
| | D) | electricity. |
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4 | | Thomson was convinced that he had discovered a subatomic particle, the electron, from the evidence that |
| | A) | the charge-to-mass ratio was the same for all materials. |
| | B) | cathode rays could move through a vacuum. |
| | C) | electrons were attracted toward a negatively charged plate. |
| | D) | the charge was always 1.60 x 10-19 coulomb. |
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5 | | The existence of a tiny, massive, and positively charged nucleus was deduced from the observation that |
| | A) | fast, massive, and positively charged alpha particles all move straight through metal foil. |
| | B) | alpha particles were deflected by a magnetic field. |
| | C) | some alpha particles were deflected by metal foil. |
| | D) | None of the above are correct. |
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6 | | According to Rutherford's calculations, the volume of an atom is mostly |
| | A) | occupied by protons and neutrons. |
| | B) | filled with electrons. |
| | C) | occupied by tightly bound protons, electrons, and neutrons. |
| | D) | empty space. |
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7 | | The atomic number is the number of |
| | A) | protons. |
| | B) | protons plus neutrons. |
| | C) | protons plus electrons. |
| | D) | protons, neutrons, and electrons in an atom. |
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8 | | All neutral atoms of an element have the same |
| | A) | atomic number. |
| | B) | number of electrons. |
| | C) | number of protons. |
| | D) | All of the above are correct. |
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9 | | The main problem with a solar system model of the atom is that |
| | A) | electrons move in circular, not elliptical orbits. |
| | B) | the electrons should lose energy since they are accelerating. |
| | C) | opposite charges should attract one another. |
| | D) | the mass ratio of the nucleus to the electrons is wrong. |
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10 | | The energy of a photon |
| | A) | varies inversely with the frequency. |
| | B) | is directly proportional to the frequency. |
| | C) | varies directly with the velocity, not the frequency. |
| | D) | is inversely proportional to the velocity. |
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11 | | The frequency of a particular color of light is equal to |
| | A) | Eh. |
| | B) | h/E. |
| | C) | E/h. |
| | D) | Eh/2. |
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12 | | A photon of which of the following has the most energy? |
| | A) | red light |
| | B) | orange light |
| | C) | green light |
| | D) | blue light |
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13 | | The lines of color in a line spectrum from a given element |
| | A) | change colors with changes in the temperature. |
| | B) | are always the same, with a regular spacing pattern. |
| | C) | are randomly spaced, having no particular pattern. |
| | D) | have the same colors, with a spacing pattern that varies with the temperature. |
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14 | | Hydrogen, with its one electron, produces a line spectrum in the visible light range with |
| | A) | one color line. |
| | B) | two color lines. |
| | C) | three color lines. |
| | D) | four color lines. |
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15 | | Using the laws of motion for moving particles and the laws of electrical attraction, Bohr calculated that electrons could |
| | A) | move only in orbits of certain allowed radii. |
| | B) | move, as do the planets, in orbits at any distance from the nucleus. |
| | C) | move in orbits at distances from the nucleus that matched the distances between colors in the line spectrum. |
| | D) | move in orbits at variable distances from the nucleus that are directly proportional to the velocity of the electrons. |
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16 | | According to the Bohr model, an electron gains or loses energy only by |
| | A) | moving faster or slower in an allowed orbit. |
| | B) | jumping from one allowed orbit to another. |
| | C) | being completely removed from an atom. |
| | D) | jumping from one atom to another atom. |
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17 | | When an electron in a hydrogen atom jumps from an orbit farther from the nucleus to an orbit closer to the nucleus, it |
| | A) | emits a single photon with an energy equal to the energy difference of the two orbits. |
| | B) | emits four photons, one for each of the color lines observed in the line spectrum of hydrogen. |
| | C) | emits a number of photons dependent on the number of orbit levels jumped over. |
| | D) | None of the above are correct. |
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18 | | The Bohr model of the atom |
| | A) | explained the color lines in the hydrogen spectrum. |
| | B) | could not explain the line spectrum of atoms larger than hydrogen. |
| | C) | had some made-up rules without explanations. |
| | D) | All of the above are correct. |
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19 | | The proposal that matter, like light, has wave properties in addition to particle properties was |
| | A) | verified by diffraction experiments with a beam of electrons. |
| | B) | never tested, since it was known to be impossible. |
| | C) | tested mathematically, but not by actual experiments. |
| | D) | verified by physical measurement of a moving baseball. |
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20 | | The quantum mechanics model of the atom is based on |
| | A) | the quanta, or measured amounts of energy of a moving particle. |
| | B) | the energy of a standing electron wave that can fit into an orbit. |
| | C) | calculations of the energy of the three-dimensional shape of a circular orbit of an electron particle. |
| | D) | Newton's laws of motion, but scaled down to the size of electron particles. |
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21 | | The Bohr model of the atom described the energy state of electrons with one quantum number. The quantum mechanics model uses how many quantum numbers to describe the energy state of an electron? |
| | A) | one |
| | B) | two |
| | C) | four |
| | D) | ten |
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22 | | An electron in the second main energy level and the second sublevel is described by the symbols |
| | A) | 1s. |
| | B) | 2s. |
| | C) | 1p. |
| | D) | 2p. |
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23 | | The space in which it is probable that an electron will be found is described by a(an) |
| | A) | circular orbit. |
| | B) | elliptical orbit. |
| | C) | orbital. |
| | D) | geocentric orbit. |
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24 | | Two electrons can occupy the same orbital because they have different |
| | A) | principal quantum numbers. |
| | B) | angular momentum quantum numbers. |
| | C) | magnetic quantum numbers. |
| | D) | spin quantum numbers. |
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