PhySci U3 QC – Flashcards
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The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided?
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atom
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According to John Dalton's observations, when elements combine in a compound,
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the ratio of their masses is always the same.
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J. J. Thomson's experiments provided evidence that an atom
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contains negatively charged particles.
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Statement that best describes Rutherford's model of the atom
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It is like a huge stadium with a positively charged marble at the center.
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What part of Rutherford's investigations demonstrated that the Thomson model was not accurate?
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They showed that the atoms have a dense nucleus.
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Which subatomic particle has a negative charge?
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electron
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The number of protons in one atom of an element is that element's
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atomic number
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Which statement about subatomic particles is NOT true?
*Protons and neutrons have almost the same mass.
*Protons and electrons have opposite charges.
*Unlike protons and electrons, neutrons have no charge.
*Protons and neutrons have the same charge.
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Protons and neutrons have the same charge.
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How many neutrons are in the isotope carbon-14
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8
Explanation:
(atomic mass 14 - atomic number 6 = 8)
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Which element has 17 protons, 17 electrons, and 18 neutrons?
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chlorine
Explanation:
atomic mass minus atomic number
35 - 17 = 18
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In Niels Bohr's model of the atom, electrons move
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like planets orbiting the sun.
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Which statement about electrons and atomic orbitals is NOT true?
*An electron has the same amount of energy in all orbitals.
*An orbital can contain a maximum of two electrons.
*An electron cloud represents all the orbitals in an atom.
*An atom's lowest energy level has only one orbital.
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An electron has the same amount of energy in all orbitals.
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The glowing of a neon light is caused by electrons emitting energy as they
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move from higher to lower energy levels.
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What do scientists use to predict the locations of electrons in atoms?
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probability
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When an atom is in an excited state,
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one or more electrons have moved from the ground state to a higher energy level.
