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1. Neutrons
are subatomic particles with a positive charge. |
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2. The
atomic nucleus contains electrons and neutrons. |
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3. All
atoms of the same element have the same number of protons. |
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4. Protons
are more massive than neutrons. |
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5. Protons
repel electrons because they have the same charge. |
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6. All
electrons have a relative minus one charge. |
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7. Electrons
repel electrons because they all have the same charge. |
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8. Atomic
numbers are all whole numbers like 1, 2, etc. |
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9. Mendeleev
proposed the forerunner of the modern periodic table |
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10. Elements
in the same vertical group show similar properties. |
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11. Horizontal
rows in the periodic table are called "periods". |
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12. Elements
in the periodic table are arranged in order of increasing atomic number. |
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13. Electrons
show magnetic character. |
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14. Valence
electrons are electrons close to the nucleus of the atom. |
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15. Chlorine
is an example of a metal. |
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16. Sodium,
Na, is a p-block element. |
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17. Isotopes
are atoms of the same element with different numbers of electrons. |
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18. The
electron configuration for the six electrons in carbon is 1s22s22p2 |
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19. The
lowest value for the quantum number "n" is zero, |
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20. An
atom with the electron configuration 1s22s2 2p1
has one valence electron. |