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Definition
| A part or particle considered to be an irreducible constituent of a specified system. |
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| The mass of an atom, usually expressed in atomic mass units. |
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Definition
| The number of protons in an atomic nucleus. |
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| A stable subatomic particle in the lepton family having a rest mass of 9.1066 × 10-28 grams and a unit negative electric charge of approximately 1.602 × 10-19 coulombs. See table at subatomic particle |
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Definition
| A fundamental, essential, or irreducible constituent of a composite entity |
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Definition
| The energy characteristic of a stationary state of a physical system, especially a quantum mechanical system |
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| One of two or more atoms having the same atomic number but different mass numbers. |
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| The sum of the number of neutrons and protons in an atomic nucleus. Also called nucleon number |
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Term
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Definition
| An electrically neutral subatomic particle in the baryon family, having a mass 1,839 times that of the electron, stable when bound in an atomic nucleus, and having a mean lifetime of approximately 1.0 × 103 seconds as a free particle. It and the proton form nearly the entire mass of atomic nuclei. See table at subatomic particle. |
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Definition
| A central or essential part around which other parts are gathered or grouped; a core: the nucleus of a city |
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Definition
| A stable, positively charged subatomic particle in the baryon family having a mass 1,836 times that of the electron. See table at subatomic particle |
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Definition
| Spontaneous emission of radiation, either directly from unstable atomic nuclei or as a consequence of a nuclear reaction |
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Definition
| An electron in an outer shell of an atom that can participate in forming chemical bonds with other atoms. |
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