atomic number


atomic number

noun

Definition of ATOMIC NUMBER

:  an experimentally determined number characteristic of a chemical element that represents the number of protons in the nucleus which in a neutral atom equals the number of electrons outside the nucleus and that determines the place of the element in the periodic table — see element table

First Known Use of ATOMIC NUMBER

1821

Rhymes with ATOMIC NUMBER

atomic num·ber

noun \-ˈnəm-bər\   (Medical Dictionary)

Medical Definition of ATOMIC NUMBER

: an experimentally determined number characteristic of a chemical element that represents the number of protons in the nucleus which in a neutral atom equals the number of electrons outside the nucleus and that determines the place of the element in the periodic table—see element table

atomic number

noun    (Concise Encyclopedia)

Number of a chemical element in the systematic, ordered sequence shown in the periodic table. The elements are arranged in order of increasing number of protons in the nucleus of the atom (the same as the number of electrons in the neutral atom), and that number for each element is its atomic number.

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