Term
| Periodic Table of Elements |
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Definition
| A table showing the chemical elements arranged according to their atomic numbers |
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Term
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Definition
The number of protons in the nucleus
of one atom of an element |
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Definition
The columns on a Periodic Table that
arrange the elements by the number of
electrons that are in the outermost shell |
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Term
| Periods on Periodic Table |
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Definition
| The rows in a Periodic Table that classify the elements by the number of electron shells |
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Term
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Definition
| Elements that have properties of both metals and nonmetals; sometimes referred to as semiconductors |
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Term
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Definition
Unreactive nonmetals in Group 18
of the Period Table |
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Term
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Definition
A specific area where electrons of the
same energy level are found |
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Definition
| A pure substance that cannot be separated into simpler substances by physical or chemical means |
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Definition
A one- or two-letter notation used to
represent an atom of a particular element |
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Term
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Definition
Stands for Atomic Mass Unit; is used to
indicate mass on an atomic or molecular scale |
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Term
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Definition
| The rate at which a chemical substance tends to undergo a chemical reaction |
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Term
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Definition
A series of metallic elements, included in the rare earth
metals listed in Group 3 of the Periodic Table |
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Term
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Definition
| The series includes the 15 metallic elements in Group 3 with atomic numbers 89-103. They are all radioactive and release energy when they decay. Some are synthetic,only formed in science laboratories. |
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Term
| Group A: Main Group Elements |
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Definition
| Elements in Periodic Table groups 1A (except hydrogen), 2A and groups 3A to 8A |
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Term
| Group B: Transition Elements |
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Definition
| The 38 elements in groups 3B, 4B, 5B, 6B, 7B, 8B, 1B, and 2B; the transition elements are both ductile and alleable and conduct electricity and heat |
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Term
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Definition
Metals found in Group 2A of the Periodic Table; all alkaline earth elements have an oxidation number of +2, making them very reactive. Because of their reactivity, the alkaline
earth metals are not found free in nature. |
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Term
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Definition
| Metals found in Group 1 of the Periodic Table (except hydrogen); compared to other metals, they are soft and have low melting points and densities |
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