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1.
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Electrons
A. | have a positive charge. | B. | determine the atomic number of an
element. | C. | have more mass than the other parts of an atom. | D. | move around outside
the nucleus. |
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2.
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One kind of uranium atom has 92 protons and 143 neutrons. Another atom of
uranium has 92 protons and 146 neutrons. The two uranium atoms are different
A. | ions. | B. | elements. | C. | electrons. | D. | isotopes. |
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3.
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Mg2+ is a magnesium ion that has
A. | two fewer electrons than a neutral magnesium atom. | B. | two fewer neutrons
than a neutral magnesium atom. | C. | two more protons than a neutral magnesium
atom. | D. | an atomic mass greater than that of a neutral magnesium
atom. |
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4.
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Atoms of an element always have a certain number of
A. | neutrons. | B. | protons. | C. | electrons. | D. | ions. |
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5.
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The total number of protons and neutrons in the nucleus determines the
atom's
A. | symbol. | B. | atomic number. | C. | atomic mass
number. | D. | size. |
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Use the visual below to answer questions 6 &
7.
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6.
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What is the atom’s atomic number?
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7.
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What is the atom’s mass number?
A. | 4 amu | B. | 5 amu | C. | 9
amu | D. | 13 amu |
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8.
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How many electrons fill the second energy level?
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9.
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The central part of the atom is called the
A. | electron. | B. | nucleus. | C. | proton. | D. | neutron. |
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10.
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Which of the following forces is responsible for holding the nucleus of an atom
together?
A. | gravitational | B. | electromagnetic | C. | strong | D. | weak |
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