单词	atomic number
释义	atomic number noun : 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 Chemical Elements Table Example Sentences Recent Examples on the Web Rare earths are a group of 17 metals, classified into lights and heavies depending on their atomic number, and are crucial to the manufacturing of high-tech products. Mary Hui, Quartz, 14 May 2021 But today who needs to know the capital of South Dakota or the atomic number of hafnium (Pierre and 72)? Louis Menand, The New Yorker, 16 Nov. 2020 Naturally occurring silicon has an atomic number of 14, with 14 electrons that are arranged in valence layers of 2, 8, and 4. Caroline Delbert, Popular Mechanics, 11 Feb. 2020 Some rare earths are heavy and some are light, depending on their atomic number, and the two have different applications. Naomi Xu Elegant, Fortune, 10 Sep. 2019 How to Read the Table Many periodic tables include the atomic number (number of protons) and atomic weight (which depends on protons and neutrons). Bill Andrews, Discover Magazine, 26 June 2019 For the types of BECs that form droplets, the repulsive forces are not just a function of the density but also the atomic number. Chris Lee, Ars Technica, 28 Nov. 2018 Among the atoms resulting from neutron bombardment were much smaller atoms like barium, which has an atomic number of 56. Umair Irfan, Vox, 11 June 2018 Here are some of the basics: Uranium is the heaviest naturally occurring element in the periodic table, with an atomic number of 92, representing the number of protons in its nucleus. Umair Irfan, Vox, 11 June 2018 See More Word History First Known Use 1913, in the meaning defined above Medical Definition atomic number noun atomic num·​ber -ˈnəm-bər  : 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 Chemical Elements Table
随便看	unalloyed unalluring unalterabilities unalterability unalterable unalterableness unalterablenesses unalterably unaltered unamalgamated unamazed unambiguities unambiguity unambiguityes unambiguitys unambiguous unambiguously unambition unambitious unambivalent unambivalently unamenable unamendable unamended Unami

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